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VOLUME 68 DECEMBER 1975 ISSN 0303 2515

{ per sie

LiBRARILS

OF THE SOUTH AFRICAN

; EOF, of

KOV-W>) DUS RO DTA

INSTRUCTIONS TO AUTHORS

1. MATERIAL should be original and not published elsewhere, in whole or in part. When

accepted, copyright becomes the property of the Trustees of the South African Museum.

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BULLOUGH, W. S. 1960. Practical invertebrate anatomy. 2nd ed. London: Macmillan.

FISCHER, P.-H. 1948. Données sur la résistance et de le vitalité des mollusques.—J. Conch., Paris 88: 100-140.

FISCHER, P.-H., DUVAL, M. & Rarry, A. 1933. Etudes sur les échanges respiratoires des littorines.—Archs

Zool. exp. gén. 74: 627-634.

Koun, A. J. 1960a. Ecological notes on Conus (Mollusca: Gastropoda) in the Trincomalee region of Ceylon.—

Ann. Mag. nat. Hist. (13) 2: 309-320.

Koun, A. J. 1960b. Spawning behaviour, egg masses and larval development in Conus from the Indian

Ocean.— Bull. Bingham oceanogr. Coll. 17 (4): 1-51.

THIELE, J. 1910. Mollusca: B. Polyplacophora, Gastropoda marina, Bivalvia. In: SCHULTZE, L. Zoologische

und anthropologische Ergebnisse einer Forschungsreise im westlichen und zentralen Siid-Afrika 4: 269-270.

Jena: Fischer.— Denkschr. med.-naturw. Ges. Jena 16: 269-270.

(continued inside back cover)

ANNALS OF THE

SOUTH AFRICAN MUSEUM

VOLUME 68

Hydrocorella africana. Colony on shell, with calcareous processes

in foreground.

Hydractinia altispina. Colony on shell, with gastrozooids and

gonozooids.

Photographs: D. Gerneke.

Tubularia warreni. Hydranth with

gonophores.

Bicorona elegans.

ANNALS OF THE SOUTH AFRICAN MUSEUM

ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM

Volume 68 Band

December 1975 Desember

MONOGRAPH ON THE HYDROIDA

OF SOUTHERN AFRICA

N. A. H. MILLARD

Cape Town Kaapstad

bale be ww I i

NWI

INSEPIULIVUIN

SMITHSONIAN

IT 1IRRARIES

NS SJIMNWNA

al rAICTITIITIOAI

AITLIC OAT

The ANNALS OF THE SOUTH AFRICAN MUSEUM

are issued in parts at irregular intervals as material

becomes available

Obtainable from the South African Museum, P.O. Box 61, Cape Town

Die ANNALE VAN DIE SUID-AFRIKAANSE MUSEUM

word uitgegee in dele op ongereelde tye na beskikbaarheid

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Verkrygbaar van die Suid-Afrikaanse Museum, Posbus 61, Kaapstad

OUT OF PRINT/UIT DRUK

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6(1, t.—p.i.), 7(1-3), 8, 911-2), 10(1),

11(1-2, 5, 7, t.—p.i.), 15(5), 24(2), 27, 31(1-3), 33

Price of this part/Prys van hierdie deel

R22,50

Trustees of the South African Museum © Trustees van die Suid-Afrikaanse Museum

1975

ISBN 0 949940 81 X

Printed in South Africa by In Suid-Afrika gedruk deur

The Rustica Press, Pty., Ltd.,

Court Road, Wynberg, Cape

Die Rustica-pers, Edms., Bpk.,

Courtweg, Wynberg, Kaap

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

N. A. H. MILLARD

South African Museum, Cape Town

(With 143 figures)

[MS. accepted 7 October 1974]

CONTENTS

Introduction

Structure and terminology

Order Hydroida

Suborder Athecata

Family Corymorphidae

Family Tubulariidae

Family Halocordylidae

Family Myriothelidae

Family Corynidae

Family Cladonemidae

Family Solanderiidae

Family Asyncorynidae

Family Cladocorynidae

Family Zancleidae

Family Clavidae p

Family Eudendriidae .

Family Bougainvilliidae

Family Hydractintidae

Family Cytaeidae

Family Pandeidae

Suborder Thecata ;

Family Campanulinidae

Family Haleciidae

Family Lafoeidae

Family Campanulariidae

Family Syntheciidae

Family Sertulariidae

Family Plumulariidae .

Subfamily Halopterinae

Subfamily Kirchenpaueriinae

Subfamily Plumulariinae

Subfamily Aglaopheniinae

Suborder Limnomedusae

Family Moerisiidae :

Family Proboscidactylidae .

List of species and authorities for previous South African records ‘

Records of hydroid medusae from the South African region .

Acknowledgements

Addendum

References

Index to scientific terms

Index to species

Ann. S. Afr. Mus. 68, 1975: 1-513, 143 figs.

NOILOLILSNI NVINOSHLIW

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SAAITHSCONIAN

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2 ANNALS OF THE SOUTH AFRICAN MUSEUM

INTRODUCTION

CONTENT AND CLASSIFICATION

This monograph deals with the hydroid fauna of the African coast south

of 20° south latitude, and as such covers all of the Republic of South Africa,

most of South West Africa and the southern part of Mocambique as far north

as Beira (Fig. 1). Seawards it covers the continental shelf and the Agulhas Bank,

where records are abundant to a depth of about 100 m but become increasingly

scarce below this.

The classification of the Hydrozoa accepted for the purpose of the mono-

graph is as follows:

Class HYDROZOA

Order 1. Hydrida

Order 2. Actinulida S

Order 3. Trachylida

Suborder 1. Trachymedusae

Suborder 2. Narcomedusae

Order 4. Hydroida (Leptolina)

Suborder 1. Athecata (Gymnoblastea, Anthomedusae)

Suborder 2. Thecata (Calyptoblastea, Leptomedusae)

Suborder 3. Chondrophora

Suborder 4. Limnomedusae

Order 5. Hydrocorallida

Suborder 1. Milleporina

Suborder 2. Stylasterina

Order 6. Siphonophora

The monograph deals with the marine and brack water Hydroida of the

suborders Athecata, Thecata and Limnomedusae. Certain authorities (parti-

cularly Picard 1957) consider that the Chondrophora (originally included in the

Siphonophora) and the Milleporina are closely related to the athecate hydroids.

Evidence in favour of such an affinity appears to be increasing, and Bouillon

(1974) evaluates these two groups as families (Velellidae and Milleporidae

respectively) of capitate athecate Hydroida. However, in the meantime I have

retained the old classification and these two groups are not covered in this

monograph.

It is usual among hydroid systematists to divide the Athecata into the

Capitata and the Filifera, a division which depends on the presence of capitate

tentacles in the former and their absence in the latter. It is felt, however, that

this fission is not a natural one and it has therefore not been used. In some genera

capitate tentacles are present in the immature stages and not in the adult (e.g.

Tubularia), while in others they are present in the medusa and not in the polyp

(e.g. Bougainvillia).

In all 286 species and subspecies are described, nine of them new to science.*

Keys to South African families, genera and species are provided. These keys do

* See also Addendum, p. 483.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

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4 ANNALS OF THE SOUTH AFRICAN MUSEUM

not necessarily represent systematic relationships but are intended as a tool for

identification only. They should be used with caution and the genera and species

checked against the diagnoses and diagrams. Material which does not fit the

keys may be new species or new records for the country. Some well-known genera

not yet recorded from South Africa have been included in the keys but are

enclosed in brackets.

The monograph is essentially on the polyp rather than the medusa genera-

tion, and the polyp generation has been emphasized throughout, both in the

keys and in the descriptions. The medusa generation is described where known,

but medusae with unknown polyps are not described. A check-list of South

African medusa records is given on p. 481.

Families are arranged in the generally accepted order, which implies a very

rough evolutionary sequence. Genera and species are arranged in alphabetical

order within the families. Each family has a short introduction outlining its

more important features.

The systematic descriptions are preceded by a section on structure and

terminology where definitions of terms will be found. Certain terms, which are

relevant to particular families only, will be defined in the introduction to those

families. The index to scientific terms on p. 497 will give quick access to

definitions.

MEASUREMENTS

Measurements are not given in detail, for they are intended only as a rough

guide to the size. Measurements of a colony are given to the nearest mm and

those of a hydrotheca to the nearest 0,1 mm except for those which are less

than 0,2 mm which are given to the nearest 0,01 mm. Measurements apply

strictly to South African material, as do numbers of tentacles, etc. The depth

of a hydrotheca is taken in side-view in the centre, unless otherwise stated, and

exclusive of regenerated margins when these occur. When the hydrothecal wall

is curved the straight measurement is taken from the base to the edge and across

the curvature.

RECORDS OF DISTRIBUTION AND DEPTH

At the end of each species the distribution in southern Africa, both from

the author’s findings and other papers, is briefly summarized. This is done by

the use of two figures indicating the latitude/longitude squares. Thus, 35/20

would indicate a latitude between 35 and 36° south and a longitude between

20 and 21° east.

The depth range is added in parenthesis, thus: 35/20 (s), where ‘s’ refers to

‘shallow’. For the depth the following key is used:

1: littoral vd: very deep (500-999 m)

s: shallow (1-99 m) a: abyssal (1 000 m and over)

d: deep (100-499 m) h: ships’ hulls and floating objects

Estuarine records have not been separated; generally they are included in ‘s’.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 5

No attempt has been made to indicate relative abundance. In the first

place most of the records are from dredgings performed in a random fashion.

In the second place many species can be identified only from fertile material,

and in such cases sterile records have been omitted rather than risk incorrect

identifications. Genera such as Eudendrium, Tubularia and Hydractinia, for

instance, are much more abundant than is indicated by the records, which are

usually of fertile material only.

Geographical distribution has not been analysed in this monograph, either

within southern Africa or as related to world distribution. The matter will be

discussed fully in a subsequent paper.

NEMATOCYSTS

Much attention has been paid in recent years to nematocyst type and its use

in classification. It appears that within most families nematocysts are not of great

diagnostic value since members of a family tend to have the same types. They

may be of great value, though, in genera with few other diagnostic characters

and are useful for establishing relationships in groups of doubtful affinity. In

this monograph they have been described, where possible, for the Athecata

only, where the diagnostic characters are fewer than in the Thecata.

For the examination of nematocysts only living material is satisfactory.

Whole tentacles, smears or portions of the body should be mounted on a

microscopic slide in sea-water. Replacement of the sea-water by distilled water

will cause discharge of many types, and further discharge may be facilitated

by alternate drying and re-hydration. Suitable stains include neutral red,

methylene blue and magenta. A powerful microscope and oil immersion lens is

necessary for observation of detail, though the category can often be determined

without strong magnification.

SYNONYMY AND REFERENCES

The synonymy given with each species is not intended to be complete, but in

each case there has been quoted the original description and, where possible, at

least one good description or reference to a synonymy.

The literature on South African hydroids is very scattered, most of the

earlier work being limited to descriptions of collections made by expeditions

passing through the area. Stechow, in 1925a, published a check-list of 153 species

up to that date. The most important records previous to 1925 are those of

Warren, who deserves special praise for the accuracy of his descriptions and

diagrams, Busk, Kirchenpauer, Allman, Ritchie, Billard, Jaderholm, Mark-

tanner-Turneretscher, Vanh6offen and Stechow himself. Kirchenpauer’s type

material was unfortunately nearly all destroyed during the last world war.

Some of his species were redescribed by Stechow (19195), but many were

inadequately described in the first place and may now be dropped. Stechow’s

slide material has been available to the author on loan. Busk’s material and

much of Allman’s material is present in the British Museum (Natural History).

6 ANNALS OF THE SOUTH AFRICAN MUSEUM

Warren’s material is in part in the British Museum and in part in the Natal

Museum. Ritchie’s collection was redescribed by Rees & Thursfield (1965).

Since 1925 the quota of species has been added to by Vervoort, Leloup,

Ewer, Kramp, Manton and the present author, and Stechow’s check-list has

been almost doubled.

In the list of references on p. 485 all those containing South African records

have been marked with an asterisk.

On p. 471 a complete list of species is given together with the authorities

for previous records. Thus, any record can be located through the index to

species on p. 499, even though it may not be quoted with the description.

SOURCES OF MATERIAL

Collections from many sources have contributed material towards this

monograph. They may be listed as follows:

The collection in the Zoology Department, University of Cape Town, consisting

of some material left by the late Professor T. A. Stephenson from his intertidal

survey of the coast, and a large body of material added more recently by Professor

J. H. Day and his colleagues during work on estuaries, the bottom fauna of the

continental shelf and the littoral area. Type specimens from this collection are

housed in the South African Museum.

The collection in the South African Museum, much of it derived from dredgings

of the s.s. Pieter Faure at the turn of the century.

The collection from Dr Th. Mortensen’s Java—South Africa Expedition,

1929-1930, and material from the Universitetets Zoologiske Museum, K¢ébenhavn.

A collection from Inhaca, Delagoa Bay, submitted by the University of the Wit-

watersrand, Johannesburg.

Material submitted by the Oceanography Department, University of Cape Town.

Material submitted by the Zoology Department, Rhodes University, Grahams-

town.

Material submitted by the Division of Sea Fisheries, Cape Town.

Material collected by the R/V Anton Bruun during the International Indian Ocean

Expedition, 1964.

Material collected by Professor J. Bouillon, Bruxelles, on the coast of Mocam-

bique in 1969.

Material collected by the author from various parts of the coast.

STRUCTURE AND TERMINOLOGY

Accounts of the detailed structure and histology of the Hydrozoa are readily

obtainable in textbooks. The present account of the anatomy does not claim to

be complete and is intended onl, to provide a glossary to the terms used in the

keys and diagnoses.

The polyp and medusa phases characteristic of-the life-history of the

Hydroida are primarily radially symmetrical, though occasionally a secondary

bilateral symmetry is superimposed. The polyp, or asexual generation, usually

multiplies by vegetative propagation to produce colonies and is typically

permanently attached to the substratum. The medusa, or sexual generation, is

free-swimming and responsible for distribution of the sexual products.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA |

The POLyP has a cylindrical body with a body-wall of ectoderm, endoderm

and mesogloea, and it contains a cavity, or COELENTERON, with a single open-

ing, the MOUTH. It consists of a base, the HYDRORHIZA, an upright stem, the

HYDROCAULUS, and a terminal part bearing the mouth and tentacles, the

HYDRANTH.

The HYDRORHIZA normally takes the form of branching tubes, or STOLONS,

which ramify over the substratum and affix the body of the animal. In certain

cases the stolons may fuse with one another to form a continuous mat, said to

be INCRUSTING (Fig. 35C). In certain mud- and sand-dwelling forms the hydro-

rhiza is in the form of slender root-like ANCHORING FILAMENTS (Fig. 13). Forms

also occur in which the hydrorhiza is provided with ATTACHMENT DISCS or

PEDAL DISCS with adhesive properties (Fig. 142).

The HYDROCAULUS rises from the hydrorhiza and bears the hydranth, from

which it is often not clearly demarcated. Its body-wall is the COENOSARC. Its

cavity provides communication between the various parts of a colony; it is

usually simple, but in some of the larger polyps may be provided with special

mouth

oral tentacle

hypostome

a ( hypostome

/ « }-gonophore LL

(medusa bud)

. ‘

Oty te ee

Hydranth

aboral

hydrotheca

tentacle

gastral cavity

perisarc

coenosarc

Hydrocaulus coelenteron

gonotheca

gonophore spadix

gonad

—stolon

Hydrorhiza

ATHECATE ip CARE

Fig. 2. Diagrammatic representation of the parts of the polyp generation.

8 ANNALS OF THE SOUTH AFRICAN MUSEUM

longitudinal ENDODERMAL CANALS, while the main lumen is filled with vacuolated

endoderm cells.

The HYDRANTH consists of a main or digestive region containing a swollen

GASTRAL CAVITY and an elongated HYPOSTOME, or manubrium, bearing the

mouth at its summit. It also bears the TENTACLES.

The endoderm of the hydranth is usually relatively undifferentiated, though

mucous cells tend to be more numerous in the hypostome and enzymatous cells

in the gastral cavity. In the Thecata the single whorl of tentacles marks a

boundary between these two regions. In some thecate families the endoderm

of the gastral cavity is differentiated into two parts which may be demarcated

externally by a groove, the enzymatous cells being concentrated in the basal

part, e.g. Haleciidae, Plumulariidae. In the Sertulariidae some genera possess a

BLIND CAECUM, or pouch of endoderm, which grows out from the basal region

and is devoid of enzymatous cells (Fig. 81A).

The cavity of the hydranth is normally simple, but in large hydranths, e.g.

Myriothelidae, the surface area may be increased by ingrowths of endoderm to

form VILLI (Fig. 18E). In the Tubulariidae a cushion of special endoderm cells

projects into the basal part of the gastral cavity functioning as a DIAPHRAGM to

prevent the passage of large food particles.

The HYPOSTOME is conical in most families, but in the Eudendriidae and

Campanulariidae tends to gape open and is trumpet-shaped.

The TENTACLES vary in structure and arrangement, and may be scattered

over the whole body of the hydranth, or concentrated into one or more whorls.

When there are two whorls these are said to be ORAL and ABORAL. Rarely

tentacles are absent, and rarely they are branched.

There are three types of tentacles:

1. MONILIFORM: very extensile tentacles, with a series of batteries of sting-cells

arranged like beads on a string.

ectoderm

endoderm

° s)° “\°7>7.

~ =

hele oe

Ee WREAK Bk OF

w* # mesogloea

{

FILIFORM SOLID

MONILIFORM BRANCHED HOLLOW

Fig. 3. Tentacle types and structure.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 9

2. CAPITATE: short tentacles terminating in a single knob-like battery of sting cells.

3. FILIFORM: long, slender tentacles in which the sting-cells are scattered along

the length and not concentrated in batteries.

In structure the tentacles may be:

1. HOLLOW, in which case they may contain a cavity lined by endoderm and com-

municating with that of the gastral cavity, but more often the inner sides of the

endodermal tube have come into juxtaposition and the cavity is lost. How-

ever, in the latter case the endoderm is always more than one layer thick.

2. SOLID, in which case there is a central core consisting of one row of large, stiff

endoderm cells.

In some of the more primitive families the bases of the tentacles may be

connected by an INTERTENTACULAR WEB (Fig. 43C).

The Hydroida are noted for their POLYMORPHISM, or ability to exist in

different forms. Not only does this term apply to the differentiation between

polyp and medusa, but there may be dimorphy or polymorphy of the polyp

stage. Thus there may be recognized:

1. GASTROZOOIDS: normal feeding individuals with mouth and well-developed

tentacles (but without tentacles in the parasitic Hydrichthys); without

reproductive organs.

2. GONOZOOIDS: reproductive individuals bearing medusa-buds or degenerate

medusae. They are usually modified gastrozooids and show various stages

in the reduction and loss of the tentacles. The conversion may occur during

the ripening of the reproductive bodies, e.g. Eudendrium. Sometimes there

is no sign of tentacles at any stage and the hydranth body forms a hollow

axis or stalk known as the BLASTOSTYLE.

3. DACTYLOZOOIDS: defensive individuals richly armed with sting-cells and with-

out the power to feed or reproduce. There are several types:

lls

GASTROZOOID GONOZOOID DACTYLOZOOIDS

tentaculozooid

————

Fig. 4. Types of individuals in polymorphic colonies.

10 ANNALS OF THE SOUTH AFRICAN MUSEUM

(i) SPIRAL ZOoIDS: modified hydranths without mouth or tentacles but with a

gastral cavity. They are characteristic of some of the Hydractiniidae and

typically perform writhing movements and tend to twist into a spiral.

(ii) TENTACULOZOOIDS: similar to tentacles in structure, with a solid core of endo-

derm cells and no mouth or gastral cavity. More delicate and slender than

spiral zooids.

(iii) NEMATOPHORES: highly extensile structures representing reduced hydranths

and without mouth or tentacles. Characteristic of the Plumulariidae, where

they may also be called sARCOSTYLES, but also occurring in a number of other

families.

The polyps of the Hydroida are occasionally solitary, as in the families

Corymorphidae and Myriothelidae, where the individuals are large and provided

with various internal elaborations of structure, but they are more often colonial

and consist of numerous individuals derived by asexual multiplication but

remaining in cellular continuity with one another.

Colonies may be STOLONIAL, where growth is horizontal and the hydranths

arise direct from a common hydrorhiza, or erect, where growth is vertical, pro-

ducing an upright hydrocaulus bearing the hydranths. Such a hydrocaulus may

be unbranched, and bear a terminal hydranth with or without a number of

lateral ones, or it may be branched.

The form of erect colonies depends primarily on the type of growth. Kuhn

(1914) defined three types of growth; and these types have been accepted by

modern systematists and are depicted in most textbooks.

1. MONOPODIAL GROWTH WITH TERMINAL HYDRANTH (raceme). The first

hydranth on the hydrocaulus is terminal. Below this is a growth-zone, and

below this a budding zone. Buds are formed in the budding zone and the

hydranth 1

6 MONOPODIAL,

TERMINAL GROWING

POINT

growth zone —33

budding zone—#:

9 «

STOLONIAL

SYMPODIAL

MONOPODIAL,

TERMINAL HYDRANTH

Fig. 5. Forms of growth and colony formation.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 11

hydrocaulus elongates above them, so that the first bud is at the base of the

stem and the youngest near the top. Each bud then grows in a similar man-

ner and several degrees of branching may occur, each branch topped by its

oldest hydranth, e.g. most Athecata: Eudendrium, Bougainvillia, Halocordyle.

2. MONOPODIAL GROWTH WITH TERMINAL GROWING POINT. There is no terminal

hydranth, but the stem is topped by a growth-zone. Below the growth-zone

is the budding zone, so that as growth proceeds the oldest hydranth is at

the base and the youngest just below the tip, e.g. Plumulariidae, most

Sertulariidae.

3. SYMPODIAL GROWTH (cyme). The first hydranth is terminal, but it has no

growth-zone and the stem does not elongate after completion. A budding

zone below the hydranth produces a branch which grows beyond the first

hydranth and is topped by the second hydranth. Continuation of this pro-

cess produces a ‘false axis’ (the SYMPpoDIUM), which is in reality formed by

successive branches (the PopIA), e.g. Haleciidae, Campanulinidae, Campanu-

lariidae. Such a stem is usually zigzag or GENICULATE.

Few of the Hydroida are completely naked; most are provided with an

external ectodermal skeleton of a horny chitinoid material. In the Athecata the

skeleton is confined to the hydrorhiza, or to the hydrorhiza and hydrocaulus,

where it encloses the stolons and coenosarc as the PERISARC. The hydranth is

usually naked, or ATHECATE, but sometimes a gelatinous or membranous exten-

sion of perisarc may enclose the base of the hydranth as the PPEUDOHYDROTHECA,

e.g. Bougainvillia, Bimeria (Fig. 33F). In the Thecata the hydranth is contained

in a cup-like skeletal structure of definite shape, the HYDROTHECA, into which it

can be partly or completely withdrawn, i.e. it is THECATE, and the reproductive

buds (GONOPHORES) are contained in a GONOTHECA.

The PERISARC of the stem is sculptured in a fashion characteristic of the

species. It is usually divided into segments, or INTERNODES, by partitions, or

NODES: the latter are penetrated centrally by the living coenosarc. Less-marked

thickenings of perisarc may form transverse ANNULATIONS, probably resulting

from growth, or internal ridges with a strengthening function, the-INTERNODAL

SEPTA. In the Thecata each internode may give origin to one or two hydro-

thecae or branches with great regularity, each from a projecting shoulder, or

APOPHYSIS.

The stem, when it consists of a single perisarc-covered tube, is said to be

UNFASCICLED. A FASCICLED stem consists of many parallel tubes intercommuni-

cating by pores at intervals (Fig. 105). The central tube is the first-formed and

the peripheral tubes grow up around it, arising either from the hydrorhiza or

from the stem itself. Branches may arise either from the axial tube or from the

peripheral tubes.

Branching of the stem may be quite irregular resulting in shrubby colonies,

e.g. Eudendrium, or it may be very regular with the type diagnostic of the genus

or species. The following main types occur, although in certain cases two or

more may be combined in the same colony:

internode — marginal tooth

ANNALS OF THE SOUTH AFRICAN MUSEUM

marginal tooth

Se ee

Sal

internal tooth

hydrotheca

diaphragm

lateral nematotheca

abcauline side adcauline side

median inferior

intrathecal s um

nematotheca a ent

—internode

hydropore internodal septum

— annulations —node

Fig. 6. Parts of the skeleton. On the left a pedicellate and radially symmetrical hydrotheca.

On the right a sessile and bilaterally symmetrical hydrotheca, with accompanying nematothecae.

are

PINNATE. The stem is plume-like with two rows of branches on opposite sides

and in the same plane. The branches may be ALTERNATE if they arise alternately

on the right and left, or opposite if they arise in pairs from the same level.

DICHOTOMOUS. The stem forks to form two limbs of equal thickness. This

process may be repeated many times and the length of the two limbs is not

necessarily the same. The colony has no obvious ‘main stem’.

WHORLED. Branches arise from the stem in whorls. In Nemertesia members of

one whorl alternate with those of the next, giving double the number of longi-

tudinal rows.

SPIRAL. Branches arise as in a pinnate stem, but the main axis is spirally twisted.

SYMPODIAL. In addition to the single erect and hydrotheca-bearing stem

resulting from sympodial growth (which is really a ‘false axis’ or SYMPODIUM,

p. 11), subsidial branches may be produced in the same way, i.e. below the

terminal hydranth. If the branches arise alternately on the right and left, a

SCORPIOID SYMPODIUM* results, if the branches always arise from the same

side, a HELICOID SYMPODIUM™%, the latter tending to curl or twist into a spiral.

Two branches arising together on right and left produce a DICHOTOMOUS

SYMPODIUM.

* These terms are not used consistently in hydroid literature. The definitions adopted here are

from Webster’s International Dictionary.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 13

ne i (h)

STOLONIAL

geniculate straight “4 (€h)

B.UNBRANCHED

alternate opposite

pinnate whorled Spiral

C.1 ORDER OF BRANCHING

D. DICHOTOMOUS

es 1

3(eh)

a 2 ORDERS OF BRANCHING = 3 ORDERS OF BRANCHING

YF vodium Yvodium

JEvosium

scorpioid helicoid dichotomous

G. SYMPODIAL BRANCHING

Fig. 7. Types of stem and branching. The hydrocladium (A) corresponds to the stem in B,

to a branch of the first order in C, to a branch of the second order in E, and to a branch of the

third order in F.

14 ANNALS OF THE SOUTH AFRICAN MUSEUM

The term HYDROCLADIUM is in use in hydroid literature, and particularly

in the Plumulariidae, for hydrotheca-bearing branches. Unfortunately it is not

always used in the same sense. Von Schenk (1965) abandoned the term and

invented a completely new terminology for the different orders of branches in

the Plumulariidae. His system is, however, cumbersome and has not been

generally accepted. Complex branching can normally be described by use of the

simple terms primary, secondary, tertiary, etc., or branches of the first, second,

third order, etc., with the retention of the well-established term HYDROCLADIA

for the final branchlets bearing hydranths or hydrothecae. The position may be

complicated in species where the colony can exist in two forms. Thus, Anten-

nella secundaria may produce both simple unbranched stems and pinnate stems.

In this case the simple stem is synonymous with a hydrocladium and with a

branch of the pinnate stem. The same position may arise in some of the Ser-

tulariidae. In colonies with irregular branching the term hydrocladium is best

avoided.

The HYDROTHECA (Fig. 6) may be without a stalk and SESSILE, or with a

stalk, or PEDICEL, and PEDICELLATE. It may be tubular, bell-shaped (CAMPAN-

ULATE), or saucer-shaped. In the Sertulariidae and Plumulariidae it is bilaterally

symmetrical, usually with one wall fused to the stem, or ADNATE. Since the

hydrotheca usually arises at an angle to the stem it is possible to distinguish

that side closer to the stem as ADCAULINE and the opposite side as ABCAULINE.

In the genus Silicularia and some species of Campanularia the hydrotheca tends

to be grossly thickened on two opposite sides, thus imparting a bilateral sym-

metry on an otherwise radially symmetrical family (the Campanulariidae)

(Fig. 66). The hydrotheca is often ornamented by transverse annulations or

longitudinal striations.

The margin of the hydrotheca may be smooth or dentate. The MARGINAL

TEETH vary in shape and number and provide a useful diagnostic character.

The hydrotheca may also have internal perisarcal thickenings. A DIA-

PHRAGM commonly occurs in the base where the hydranth narrows to join the

coenosarc. A true diaphragm takes the form of a definite perisarcal shelf on

which the base of the hydranth rests, e.g. Clytia, Obelia; sometimes an ANNULAR

THICKENING Of a less definite nature occupies the same position (Fig. 66). In the

sessile and bilaterally symmetrical hydrothecae of the Sertulariidae and Plumu-

lariidae there is an inturned base similar in appearance to a diaphragm. It is

penetrated by the HYDROPORE.

Internal and transverse shelves or ridges of perisarc in the hydrotheca are

termed INTRATHECAL SEPTA. These may form useful attachment points for the

hydranth, facilitating its withdrawal.

INTERNAL TEETH, situated within the hydrotheca just below the margin, are

characteristic of certain Sertulariidae. Their function is not clear; the number

and position are diagnostic in certain species.

In certain families the hydrotheca is provided with a lid, or OPERCULUM,

consisting of one or more valves meeting in the centre. Broch (1918) showed

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA is

that in some members of the Campanulinidae the opercular valves are formed

from the distal part of the hydrotheca, and simply fold inwards to close the

aperture. In other campanulinids and in the Sertulariidae the operculum is

formed from the primary covering of the hydrotheca and the opercular seg-

ments are seated and hinged in embayments of the hydrothecal margin.

The arrangement of the hydrothecae on the stem and branches varies.

There may be a single row of hydrothecae on one surface, two rows of hydro-

thecae on opposite surfaces (with OPPOSITE or ALTERNATE arrangement), many

longitudinal rows, or the arrangement may be quite irregular. If the hydrothe-

cae are not quite opposite or not quite alternate the terms SUBOPPOSITE and

SUBALTERNATE are used. When the hydrothecae are borne on one surface, or face

towards one surface, that surface is said to be the ANTERIOR FACE and the

opposite surface the POSTERIOR FACE. Hydrothecae may be borne on the stem

(CAULINE HYDROTHECAE) and all its branches, or they may be restricted to the

branches or the hydrocladia.

NEMATOTHECAE contain the nematophores. They are characteristic of the

Plumulariidae and a few genera of Lafoeidae and Haleciidae. They may be

sessile or pedicellate, one-chambered or two-chambered, movable or immovable.

They may be quite irregularly arranged on the colony, or grouped in a definite

manner around the hydrothecae. In the Plumulariidae there is typically one

below each hydrotheca, the MEDIAN INFERIOR NEMATOTHECA, and one on each

side, the LATERAL NEMATOTHECAE (Fig. 6). There may also be one or two above

the hydrotheca, the SUPERIOR NEMATOTHECAE, and some on the stem, CAULINE

NEMATOTHECAE (Fig. 106).

The GONOTHECA encloses the reproductive bodies of the hydranth genera-

tion (GONOPHORES). It is usually more or less spindle-shaped, and may be smooth,

annulated or spiny, and may be provided with an operculum. The gonothecae

7” _nematophore

naked sarcophore

proximal chamber

1-CHAMBERED

ABSENT

2-CHAMBERED REDUCED

Fig. 8. Types of nematothecae.

16 ANNALS OF THE SOUTH AFRICAN MUSEUM

may be borne singly, or may be aggregated into compound bodies or protected

by special outgrowths.

In the Lafoeidae aggregations of gonothecae, often accompanied by spe-

cially modified nematothecae, form COPPINIAE, or nest-like structures round the

larger stems. In the plumulariid genera Ag/aophenia and Thecocarpus aggrega-

tions of gonothecae are borne on specially modified hydrocladia forming

CORBULAE. Protective branchlets for the gonothecae are termed PHYLACTOCARPS.

They may be formed from a modified hydrocladium or as an appendage to a

hydrocladium.

arn,

= — <_

~~ we

Modified Appendage of

hydrocladium hydrocladium

UNPROTECTED CORBULA COPPINIA PHYLACTOCARPS

Fig. 9. Types of structures protecting the gonothecae.

In addition to the external skeleton considered so far, some hydroids

possess an INTERNAL SKELETON in the sense that it is contained within, or covered

by, living cells. However, such a skeleton is always ectodermal in origin and its

position is probably secondary. In Hydractinia, for example, the adpressed

stolons of the hydrorhiza may lose the outer perisarc during development, so

that the layer is covered externally by epitheltum—the NAKED COENOSARC.

The basal layer of perisarc may produce spines which penetrate the surface.

Hydrocorella is similar, except that the skeleton is impregnated with lime. In

Rosalinda and Teissiera the internal skeleton of the hydrorhiza consists of anasto-

mosing ribs, or TRABECULAE, which produce spines. The culmination of this pro-

cess is reached in Solanderia where the trabeculae rise up to form an erect and

elaborately branching stem, covered superficially by naked ectoderm.

A typical MEDUSA is radially symmetrical with a convex upper surface, the

EXUMBRELLA, and concave lower surface, the SUBUMBRELLA. The shape varies

from flat and disc-shaped to deep bell-shaped or conical. The mouth is borne on

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA iy

apical process stomach

apical canal

hypostome

exumbrella

radial canal

subumbrella

subumbrellar oral tentacle

cavity gonad

circular canal

marginal bulb —@y¥ ocellus

& ff

4 Se §s— abaxial Surf.

marginal tentacle jf

Ss > velum oe adaxial surf.

interradius a 4

adradius ré eich

perradius 2 statocyst

Fig. 10. Composite diagram of medusa to illustrate parts.

a HYPOSTOME, or manubrium, which hangs from the centre, and opens into a

STOMACH, or gastral cavity. From the latter lead RADIAL CANALS, which com-

municate with a CIRCULAR CANAL round the margin. From the margin a VELUM,

or horizontal ectodermal shelf, projects inwards and demarcates a SUBUMBREL-

LAR CAVITY within the bell. The margin also bears the MARGINAL TENTACLES.

At the top of the exumbrella a projecting cone may form an APICAL PROCESS

and may contain an APICAL CANAL communicating with the stomach.

The RADIAL CANALS are usually four in number and impart a tetramerous

symmetry to the whole. From their position the ‘axes’ or radii of the medusa are

derived. The radial canals lie in the PERRADI; alternating with these are the

INTERRADII, and between the perradii and the interradii are the ADRADII.

Occasionally the radial canals are branched or multiplied.

The MOUTH may be simple and circular, e.g. Sarsia, or it may be drawn out

into ORAL LIPS which may be folded or crenulated, e.g. Leuckartiara. It may

also bear simple or branched ORAL TENTACLES. The latter may be borne on the

edge of the mouth or may be set back, as in Bougainvillia, so as to arise just

above it.

The STOMACH and HYPOSTOME may be short, not reaching the edge of the bell,

or may be long and extensile, hanging well below the bell. The jelly of the upper

part of the bell may bulge down into the base of the stomach forming a

PEDUNCLE.

The MARGINAL TENTACLES may be SOLID or HOLLOW, FILIFORM, CAPITATE Or

MONILIFORM, these terms being used as in the hydranth (Fig. 3). They arise from

a swelling of the margin, the MARGINAL BULB. but in some Limnomedusae this

18 ANNALS OF THE SOUTH AFRICAN MUSEUM

bulb is absent. There is usually a tentacle to each bulb, but occasionally marginal

bulbs lack tentacles or one bulb bears a group of tentacles. Rarely the tentacles

are branched (Cladonemidae). The surface of the tentacle facing towards the

centre is said to be ADAXIAL and the outer surface ABAXIAL. In addition to nor-

mal tentacles, reduced tentacles or CIRRI may occur; these are without marginal

bulbs and may be spirally coiled.

The medusa bears the sexual products in GONADS. The gonads are borne

either

(1) on the stomach wall, where they may form a single mass surrounding the

stomach or be split into horizontal or radial segments, or

(2) on the radial canals, where they may vary in shape (oval or elongated,

folded, sinuous, flattened, etc.).

Gonads borne on the stomach may, however, also spread on to the radial

canals, and those on the radial canals may reach the stomach at their inner

ends.

Most medusae possess SENSE-ORGANS, normally borne on or near the margin.

Several types occur:

1. STATOCYSTS, or organs or orientation and equilibrium. They are absent in

the Athecata, but occur in the Thecata and Limnomedusae. There are two

kinds:

(i) ECTODERMAL STATOCYSTS (MARGINAL VESICLES), in the form of hollow pits

or vesicles situated in the velum and lined by ectoderm. They contain

STATOLITHS, or concretions of calcium carbonate. They may be open,

with an opening facing towards the subumbrellar cavity, or closed, when

they hang below the velum.

(ji) ENDODERMAL STATOCYSTS, in the form of sensory clubs growing from the

circular canal. There is a solid axis of endodermal cells of which one or

two terminal ones contain concretions. They may be free, and project

through the margin of the bell, or enclosed, and contained in an ecto-

dermal vesicle.

2. OCELLI, or organs of sight, borne on the marginal bulbs and either adaxial

or abaxial in position. The structure varies from simple patches of red,

brown or black pigment to elaborate organs containing a lens.

3. CORDYLI, club-like structures of unknown function borne on the bell margin.

Medusae may also possess so-called EXCRETORY PORES, which are openings

from the radial canals to the subumbrellar surface.

The typical medusa is free-swimming and able to feed and grow, but

among the hydroids there are numerous cases where the medusa remains

attached to the hydranth as a gonophore and is reduced to a varying degree; its

development appears to be arrested at a certain stage. It is usual to distinguish

the following stages in medusa reduction (originally defined by Kiihn 1914):

|. EUMEDUSOID. Marginal tentacles and sense organs absent or reduced. No

mouth. Velum not penetrated. Radial canals present, but sometimes without

a cavity. May be freed and perform pulsations, but cannot feed or develop

fully.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 19

eA—reduced marginal

tentacle

erst

CN 7 weve eS

Mh, >

subumbrellar

cavity

gonad

hypostome

rss

Ay,

—

oan Ey

5 DD.

EUMEDUSOID nats CRYPTOMEDUSOID

(AIOS

Bones:

y=)

SSO

' oO

ne Lo}

emerem ectoderm aN

Tir endoderm \

MOTTE

HETEROMEDUSOID STYLOID

Fig. 11. Types of degenerate medusae (fixed sporosacs).

2. CRYPTOMEDUSOID. Radial canals absent, but a single layer of endoderm, the

ENDODERMAL LAMELLA, present lining the exumbrellar ectoderm. Subum-

brellar cavity distinct, reduced or absent.

3. HETEROMEDUSOID. Endodermal lamella absent. Outer ectoderm two or more-

layered, often enclosing the remnant of a subumbrellar cavity. This may

form an ACROCYSsT for the retention of eggs.

4. styLorp. A simple evagination covered with ectoderm and lined with endo-

derm; the latter with its cavity forming the sPpADIx. The sex cells develop

between the two layers.

These stages have a doubtful value in classification since some species are

sexually dimorphic, with one sex more reduced than the other, e.g. in Tubularia

indivisa and T. regalis the male gonophore is cryptomedusoid and the female

eumedusoid, and in Eulaomedea flexuosa and E. calceolifera the male gonophore

is styloid and the female heteromedusoid. It is, however, important to distinguish

between medusae which develop fully and can be keyed out by typical adult

characters and those which are degenerate and cannot feed or grow. I therefore

propose to follow Rees’s dictum (1957) and retain ‘separate genera for hydroids

with fixed gonophores and for hydroids with free medusae .. ... The term

FIXED SPOROSACS will be used for all degenerate medusoid stages, including the

four described above.

20 ANNALS OF THE SOUTH AFRICAN MUSEUM

It is thus apparent that although in the ‘typical hydroid’ the polyp and

medusa stages alternate and are of more or less equal importance, in some fami-

lies, and particularly in the Plumulariidae and Sertulariidae where fixed sporo-

sacs are the rule, evolution in the polyp generation has outpaced that in the

medusa. In contrast there are some families in which the evolution of the

medusa generation is highly advanced while the polyp is small and inconspic-

uous. In these cases the hydranth, if known, is often of little use in diagnosis and

keys have of necessity to be based on the medusae. This applies to the Lim-

nomedusae, the Campanulinidae and to several families of Athecata.

Species are said to be MONOECIOUS if the male and female sex products are

borne on the same colony or individual, and DIOECIOUS if on separate colonies

or individuals. Hermaphrodite individuals occur rarely.

Development of the fertilized egg produces two kinds of larvae:

1. The PLANULA, an oval or pear-shaped, ciliated body consisting of solid

endoderm surrounded by ectoderm (Fig. 34D). It settles to the bottom,

attaches by the broader anterior end and develops into a polyp.

2. The ACTINULA, resembling a small polyp with two circles of tentacles (Fig.

15D). It settles to the bottom where it rests on the aboral tentacles, attaches

by the aboral end and develops into a polyp.

The eggs may be fertilized in the sea or be retained in the gonophore of the

polyp generation or gonad of the medusa for the initial stages of development.

In some Thecata the eggs may be extruded from the gonotheca but retained in an

ACRocyYsT for the initial stages of development. Special brood-chambers or

MARSUPIA may also occur.

THE STING CELLS

Sting-cells, or NEMATOCYSTS (CNIDOCYSTS), are always present, and are

particularly abundant on the tentacles, the hypostome and certain special tracts

on the hydranth and medusa.

The nematocyst consists of a round, oval or elongated CAPSULE, contain-

ing a coiled TUBE. It discharges the tube by eversion. The tube may or may not

have a thicker basal portion, the BUTT, and is usually armed in part or in whole

by spirally arranged SPINES.

The classification of nematocyst types presented by Weill (1934) has been

adopted here. Weill originally distinguished 17 types in the Cnidaria; since then

additional types have been named, and in 1974 Mariscal listed a total of 26.

Not all of these occur in the Hydroida. A key to the identification of the most

common hydroid types is given below.

1. Discharged tube rolled up like a corkscrew, tube closed at tip DESMONEME (volvent)

— Discharged tube not rolled up, tube open at tip A = ks a ty 2

2. Without butt (HAPLONEME) he A “if - bd re a Se 3

— With butt (HETERONEME) .. a bie Ed a er bi ve #s 6

3. Tube tapering and slightly thicker at base (ANISORHIZA), armed, and with larger spines

near base he ie HETEROTRICHOUS ANISORHIZA

- Tube of equal diameter throughout (IsORHIZA) , ae ben ae ms bye 4

Baie cnet cease

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 21

Tube without well-defined spines (glutinant) Ki om ar ATRICHOUS ISORHIZA

Tube with well-defined spines he P aK ae iw a “2 is 5

Spines in basal region only e6 bi he ag He BASITRICHOUS ISORHIZA

Spines in middle region only we .. |_MEROTRICHOUS ISORHIZA

Butt of equal diameter throughout, tube araaued eae butt i tea ans i 7

Butt of unequal diameter ; te Y rf , AG Pe 8

Butt not more than 3 times length of capsule We See MICROBASIC MASTIGOPHORE

Butt at least 4 times length of capsule .. oe oe MACROBASIC MASTIGOPHORE

Butt dilated at base ; at an ie as STENOTELE (penetrant)

Butt dilated at distal end (EURYTELE) ae a i i Bs sel op? 9

Butt not more than 3 times length of capsule .. Be ae MICROBASIC EURYTELE

Butt at least 4 times length of capsule .. x. Ms oe MACROBASIC EURYTELE

The total ensemble of nematocyst types possessed by a species is known as

its CNIDOME.

Nematocysts are occasionally concentrated on special stalks or processes

known as CNIDOPHORES. These may occur in the polyp generation (e.g. Euden-

drium racemosum) or in the medusa (Zanclea, Proboscidactyla).

—tube

UNDISCHARGED

DISCHARGED

WW Ot w

= Qs Oa a nL O w Ow i“ oO Siar

Lu OQ= as A= DN DS DO uw WwW M iw

= Se Se Ss <> == K fF te

O = oO & Bee 5& oO co O co > oO >

= ee =O = © = © Oo O06 Z Ox Oa

” pe ry “rn ace ro xo WW ox > eS

Lu A= ie KE = @©n= Or _ oo O w

= x < a A O Sb IE e = x

oc cp) Ss” S

WW <

is = WwW < <

Ww = => =

Fig. 12. Nematocyst structure and type.

22 ANNALS OF THE SOUTH AFRICAN MUSEUM

ECOLOGY

ASEXUAL REPRODUCTION is reponsible for colony-formation and budding

off of medusae. A form of asexual reproduction known as STOLONIZATION may

also occur in the polyp generation, when the ends of the stem or branches pro-

duce tendril-like stolons which reattach and form new colonies. Sometimes the

ends of such stolons separate off (SCHIZOGENY) forming bodies similar to planu-

lae, e.g. Coryne pusilla (Fig. 19G).

BUDDING of medusae may also occur, either from the stomach wall (e.g.

Rathkea) or from the marginal bulbs (Hybocodon). FISSION is more rare, but

occurs in Staurocladia and Craspedacusta. The medusa Cytaeis tetrastyla buds

off young hydranths from the stomach wall (Kramp 1959).

REGENERATION, or regrowth after injury, is common. Colonies may die

down and regenerate later from the hydrorhiza or from the hydrocaulus. Many

forms are provided with HINGE-JOINTS (Fig. 78, 115C), which are strongly marked

oblique nodes in the perisarc where movement can occur and where rupture is

easy (comparable to the ‘breaking point’ in a lizard’s tail). Hinge-joints often

occur in pairs with a short internode between them.

In the Thecata regeneration of hydrothecae may occur. In Halecium the

new hydrotheca develops from within the old one and repetition of this process

results in a tier of hydrothecae one within the other (Fig. 46). Sometimes only

the margin regenerates resulting in a hydrotheca with numerous margins and

often adding considerably to the depth (Fig. 56A). This is common in the Lafoei-

dae and Sertulariidae.

In the Moerisiidae special resting bodies or PODOCYSTS can survive death

of the colony to regenerate later.

The Hydroida often have close relationships with other animals. The lar-

vae may settle and grow on almost any animal, including other hydroids, simply

using them as a convenient substratum. Such forms are said to be EPIZOOTIC.

In some cases the relationship is closer, and there seems to be a definite selec-

tion of the host by the epizoite. Hydroids which live on the shells of molluscs

or hermits are well known and are well represented in South Africa. It is often

difficult to draw a boundary between epizoism and COMMENSALISM, where

both animals obtain benefit from the association. Proboscidactyla (Lar), which

lives on polychaet tubes, has been proved to be an obligatory commensal.

Table 1 gives a list of South African host animals and the hydroids which

have been recorded on them as epizooites, commensals or parasites, but

hydroids acting as hosts have not been included. In addition to these, sessile

barnacles, the common shore mussels and the red-bait Pyura may carry a thick

population of hydroids.

In a few members of the Plumulariidae and Lafoeidae colonies may be

epizootic on the same species of hydroid or on closely related species. Such

forms are said to be AUTO-EPIZOOTIC (Millard 1973). This commonly results in

the stunting of the epizoite in whole or in part, so that its appearance is abnormal,

and it is difficult to recognize.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 23

Some hydroids occur only on algae and may have special adaptations for

this substratum. In Plumularia filicaulis the gonothecae are recumbent and

cemented to the alga. In Lineolaria the hydrothecae are fused for almost their

entire length to the alga.

Table 1

A list of host animals with their recorded hydroid epizoites, commensals or parasites.

Host

SPONGES

CORALS

POLY ZOA

POLYCHAETS

Laonome sp.

Sabella penicillus L.

CIRRIPEDES (stalked)

Lepas sp.

ISOPODS (parasitic)

Codonophilus (Meinertia)

imbricata (Fabr.)

HERMITS

2? Anapagurus hendersoni Barn.

Clibanarius sp.

Dardanus arrosor (Herbst)

99 99

Diogenes brevirostris Stimps.

Diogenes costatus (Fabr.)

Eupagurus placens Stebb.

DECAPODS

Halicarcinus sp.

Hymenosoma orbiculare Desm.

Jasus lalandii (M. Edw.)

BIVALVES

Crassatella capensis Lamy

GASTROPODS

Argobuccinum argus (Gm.)

Astraea tayloriana (Smith)

Bullia annulata (Lam.)

Bullia laevissima (Gm.)

Cancellaria sp.

Fusus verruculatus Lam.

Melapium lineatum (Lam.)

Nassa analogica Sow.

Nassa arcularia L.

Nassa coronata Brug.

Nassa fenestrata Marr.

Nassa kraussiana (Dunk.)

Nassa speciosa Adams

Hydroid

Hybocodon unicus

Zyzzyzus solitarius

Sphaerocoryne bedoti

Zanclea sp.

Proboscidactyla sp.

Clytia hemisphaerica

Clytia hummelinki

Obelia dichotoma

Bougainvillia meinertiae

Dicoryne conferta

Hydrocorella africana

Clavactinia multitentaculata

Hydrocorella africana

Hydractinia diogenes

Hydrocorella africana

Leuckartiara octona

Clytia hemisphaerica

Obelia geniculata

Merona cornucopiae

Hydrocorella africana

Clavactinia multitentaculata

Leuckartiara octona

Hydrocorella africana

Leuckartiara octona

Hydrocorella africana

Cytaeis nassa

Hydractinia kaffraria

Hydrocorella africana

Hydractinia marsupialia

Leuckartiara octona

Family

Tubulariidae

Corynidae

Zancleidae

Proboscidactylidae

Campanulariidae

Bougainvilliidae ©

Bougainvilliidae

Hydractiniidae

Pandeidae

Campanulariidae

Clavidae

Hydractiniidae

Pandeidae

Hydractiniidae

Pandeidae

Hydractiniidae

Cytaeidae

Hydractiniidae

Pandeidae

24 ANNALS OF THE SOUTH AFRICAN MUSEUM

Table 1 (cont.)

Host Hydroid Family

Thais squamosa (Lam.) Hydractinia altispina Hydractinitidae

Turbo sarmaticus L. Hydrocorella africana Hydractiniidae

i x Clavactinia multitentaculata Hydractiniidae

Turitella sp. Hydrocorella africana Hydractintidae

Vermetus sp. Hydrocorella africana Hydractintidae

PTEROPODS

Diacria trispinosa Les. Clytia gravieri Campanulariidae

FISH

Ambassis safgha (Forsk.) Hydrichthys boycei Pandeidae

Chaetodon lunula (Lac.) Hydrichthys boycei Pandeidae

Mugil sp. Hydrichthys boycei Pandeidae

Squalus fernandinus Molina Obelia dichotoma Campanulartidae

TURTLES

Caretta caretta (L.) Obelia dichotoma Campanulariidae

Eretmochelys imbricata (L.) Clytia hemisphaerica Campanulariidae

N.B. Ritchie (19075) records Nassa crepidula as a host for Podocoryne carnea, and Stechow

(1925a) records Oliva auricularia as a host for Hydrocorella africana and Sipho islandicus

for Stylactis siphonis. These three molluscs are not known from South Africa and are

omitted from the table.

ORDER HYDROIDA

Diagnosis. Hydrozoa typically with alternating asexual polyp and sexual medusa

generations. Polyp generation typically sedentary, rarely planktonic, with peri-

sarc and well-developed tentacles. Medusa generation budded from polyp

generation and typically free-swimming though sometimes reduced to a fixed

sporosac; with velum and sense-organs in the form of ocelli, statocysts or cordyll.

KEY TO SUBORDERS

1. Polyp generation planktonic, in the form of eee colonies with a central

gastrozooid ' ie sei

Polyp generation usually sedentary, if planktonic non as above 8 2D

2. Hydranth with a definite hydrotheca of definite shape. Medusa, when prone

usually flattened; with gonads on radial canals; with or without statocysts and if

present ectodermal ; : THECATA p. 125

— Hydranth with no definite hydrotheca. Medusa, wheal present, usually deep; with

gonads on radial canals or stomach; with or without statocysts and if present

endodermal ate ; : : ; ne fy a af 3

3. Medusa without sist OCpEEs aad “geal th aca with gonads on stomach

ATHECATA p. 24

-— Medusa with or without statocysts, without ocelli; with gonads on stomach or

radial canals ne a ve A fy ies ae LIMNOMEDUSAE p. 464

SUBORDER ATHECATA

Diagnosis. Hydranth with no definite hydrotheca or gonotheca, though a gela-

tinous or membranous pseudohydrotheca may cover the base of the body. Pro-

ducing fixed sporosacs or free medusae. Medusa usually deep bell-shaped;

with gonads on stomach but rarely extending perradially on subumbrella;

without statocysts; usually with ocelli.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

KEY TO FAMILIES

[Families in which the polyp generation is not represented in South Africa are bracketed]

Mature hydranth with at least some tentacles capitate (with the exception of one

non-South African genus of Zancleidae: Pteroclava), or with tentacles absent. If

absent, hydranth not parasitic ..

Mature hydranth with all tentacles filiform (with a few exceptions in non- n-South

African genera of ee or with tentacles absent. If absent, hydranth

parasitic ae ae Bn

Hydranths Ree

Hydranths colonial, united by a a common hydrocaulus or hydrorhiza

Hydranth tentacles all capitate, numerous and scattered .. MYRIOTHELIDAE,

At least some tentacles not capitate, at least some arranged in definite whorls

Oral tentacles scattered and eee aboral tentacles in one whorl and filiform

(or rarely absent) : [ACAULIDAE]

Tentacles in three whorls, one oral and capitate, ‘two aboral and imperfectly

moniliform a ute es [TRICYCLUSIDAE |

Hydranth with capitate net utes ee ae Pranehed’ aboral tentacles bearing

several rows of capitulae : fe oe .. _CLADOCORYNIDAE,

Hydranth without ‘branched’ tentacles

Skeleton internal . ,

Skeleton, if present, external

Skeleton forming erect, branching stems ae * - SOLANDERIIDAE,

Skeleton restricted to incrusting hydrorhiza se ae ee Ls

Hydranth with an oral whorl of capitate tentacles only .. [HYDROCORYNIDAE]

Hydranth with scattered capitate tentacles .. : : .. ZANCLEIDAE,

Stem pinnate. Aboral tentacles of hydranth ne filiform a in one whorl; oral

tentacles capitate and scattered .. |HALOCORDYLIDAE,

Stem not pinnate. Tentacles of hydranth not as 5 above

Oral tentacles in one whorl, capitate; aboral tentacles ieiteeted: oak:

form 2 ASYNCORYNIDAE,

All tentacles usually capitate, sometimes an 1 aboral whorl of vestigial filiform

tentacles as well, rarely tentacles absent

Medusa, when present, with simple tubular mouth and 24 simple renal ae

tacles. Polyp generation stolonial or with erect branched stem with firm peri-

sarc ‘ .. CORYNIDAE,

Medusa, when present, not as “above. Polyp pencratiod always stolonial, often

polymorphic

Hydranth with seas fenicles: Medusa mith 2-4 ster eel feniaeles Peano

stalked cnidophores ee ZANCLEIDAE,

Hydranth with one whorl of capitate tentacles or tentacles absent. Medusa, when

present, without cnidophores

Hydranth with one whorl of capitate a nciee Ee or tion a Pega ee of

aboral filiform tentacles. Medusa creeping, with numerous branched tentacles

provided with adhesive discs .. CLADONEMIDAE,

Colony poly- or dimorphic, with Eocene and ‘dactylozooids, of which at

least some lack tentacles. Producing fixed sporosacs

Gastrozooids and dactylozooids without tentacles, but with eae or Satie

nematocyst clusters es .. [HALOCORYNIDAE]

Gastrozooids without tentacles, dactylozooids sith one whorl of capitate ten-

tacles a ‘ : ts a [PTILOCODIIDAE]

. Hydranth with two 5 ations of aticles: one oral and one aboral, with gonophores

borne on blastostyles between them

Hydranth not as above ee : ees 7 ae x.

Hydranth pelagic, solitary and hee stem aA oe [MARGELOPSIDAE]

Hydranth sedentary, with well-developed stem

26 ANNALS OF THE SOUTH AFRICAN MUSEUM

17. Stem with perisarc, which reaches to base of hydranth body and is usually

stiff fa TUBULARIIDAE, p. 30

— Perisarc feebly developed, restricted ‘to base of stem. Anchoring filaments

present 7: : — CORYMORPHIDAE, p. 26

18. Hydranth patios ceraealaly Scan over odie iedtren, when present, with 4

lips with a continuous row of nematocyst clusters along margin .. CLAVIDAE, p. 69

— Hydranth tentacles concentrated at oral end, either in one whorl or 2-4 whorls

close together, or tentacles absent a Bs: 19

19. Hydranth with trumpet-shaped hypostome. Ne medics Spores bore on

body of hydranth below tentacles ass oe EUDENDRIIDAE, p. 77

— Hydranth with conical hypostome. Medusa resent ¢ or Pabeent ye 20

20. -Hydranth borne on definite perisarc-covered stem which is usually prance

Medusa, when present, with branched or unbranched oral tentacles inserted

above mouth-rim, marginal tentacles often in groups BOUGAINVILLIIDAE, p. 88

— Polyp generation stolonial. Medusa, when present, not as above : 21

21. Medusa with unbranched oral tentacles borne on mouth-rim and 4 niece

tentacles. Hydranths never polymorphic; medusa-buds borne directly on hydro-

rhiza - .. CYTAEIDAE, p. 118

— Medusa, when present, without true oral tentacles, but with 4 oe which may be

drawn out to form oralarms .. : f ; 22

22. Medusa, when present, with 4 oral arms Setar eles of hemaicce Risheanits

naked ee 23

— Medusa without oral arms; lips usually without clusters of nematocysts. Hydranth

with or without perisarc ee 24

23. Medusa, when present, with solitary atcinal onecles reagdhernihs polvaionahe

with gonophores borne on gonozooids 3 Br HYDRACTINIIDAE p. 104

— Medusa with marginal tentacles in 8 groups. Eebdieamtine not polymorphic, with

very extensile thread-like tentacles; medusa-buds borne directly on hydro-

rhiza har ‘ : ae ae [RATHKEIDAE ]

24. Marginal tentacles of aedte svelte at ns HnGoe a terminal cluster of nemato-

cysts .. PANDEIDAE p. 121

— Marginal tentacles at educa not evollen at base, atta a femme cluster of nemato-

cysts 2 on ae ze Pe i Ws ae [CALYCOPSIDAE]

Family Corymorphidae

Diagnosis. Large, solitary hydroids with a cylindrical hydrocaulus and terminal

hydranth. Perisarc feebly developed. Hydrocaulus usually with anchoring

filaments. Hydranth with conical hypostome and two sets of tentacles: oral and

aboral. Oral tentacles filiform, moniliform or capitate. Aboral tentacles filiform

or moniliform. Gonophores borne immediately above aboral tentacles, usually

on branching blastostyles, in the form of fixed sporosacs or free medusae.

Medusa, when present, with simple circular mouth, four radial canals and

one to four capitate or moniliform marginal tentacles. No exumbrellar nema-

tocyst tracts or ocelli. Gonad completely surrounding hypostome.

Introduction. There are several theories on evolution among the athecate fami-

lies. Rees (1957) believes that the basic stock is to be found amongst the simpler

Corymorphidae, e.g. Euphysa aurata Forbes, where the hydranths are of simple

construction, with two whorls of tentacles and poorly developed perisarc.

Within the family, however, there has been a trend among certain forms to an

increase in size and elaboration of structure, culminating in the giant Branchio-

cerianthus. These structural elaborations include:

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA ps) |

1. The presence of longitudinal ENDODERMAL CANALS in the hydrocaulus, e.g.

Corymorpha and Branchiocerianthus. These occur in the periphery of an other-

wise diffuse and parenchymatous endoderm which often fills the whole cavity

of the coenosarc.

2. The presence of a transverse DIAPHRAGM Of soft tissue in the hydranth dividing

the cavity into an oral and an aboral chamber, presumably for the support

of the aboral tentacles. (This diaphragm is not comparable with that found in

the Thecata.)

3. The elaboration of a system of branched or unbranched ‘RADIAL CANALS’ in the

hydranth immediately above the diaphragm.

4. An increase in the number of tentacles.

5. The development of a bilateral symmetry in Branchiocerianthus to permit feed-

ing in strong currents at great depths.

The perisarc is in general poorly developed and in the form of a gelatinous

sheath, which sometimes fits quite loosely. It never extends on to the body of the

hydranth and is- usually restricted to the basal part of the hydrocaulus. In

Branchiocerianthus and Corymorpha the hydrorhiza is in the form of ANCHORING

FILAMENTS, Slender root-like tubes covered with thin perisarc. These are adapta-

tions for anchoring the body in a substratum of mud or sand.

Tentacles are always in two sets, oral and aboral, and may be moniliform,

capitate or filiform.

The aboral tentacles are usually in one whorl, but the oral tentacles may be

in several, or many, close whorls concentrated around the mouth.

The gonophores are borne immediately above the aboral tentacles, usually

on hollow, branching blastostyles. They may develop into free medusae or

remain attached as fixed sporosacs. In many medusa species the hydranth

generation is still unknown.

The subdivision of the Corymorphidae is still far from settled. It has been

discussed in papers by Rees (1938, 1957), Kramp (1949) and Prévot

(959):

In the key which follows only a few of the more important genera with

known hydranth generations have been included, arid the diagnostic characters

have been taken from Brinckmann-Voss (1970).

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Hydranth bilaterally symmetrical, with two sets of filiform tentacles

Branchiocerianthus p. 28

Hydranth radially symmetrical .. x : , , as 2,

2. Hydranth with two sets of filiform tentacles. iitedinge with pointed Seca process

and one moniliform tentacle : .. Corymorpha p. 30

— Hydranth with all tentacles not filiform. Medusa, when present, without apical

process a : : ce ; 3

3. Hydranth with capitate or arson eel feniacls iE Onlifo poral araeles

Medusa with 1-4 moniliform tentacles ny [Euphysa]

— Hydranth with moniliform oral tentacles, Fsioaat aiarel ines. Medusa with one

Capitate tentacle .. Ba me sn aya oe a .. [Vannuccia]

28 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Branchiocerianthus Mark, 1898

Syn. Branchiaria Stechow, 1921.

Diagnosis. Hydranth bilaterally symmetrical and excentrically seated on

hydrocaulus, with diaphragm, radial canals and two sets of filiform tentacles.

Hydrocaulus rooted by anchoring filaments. Perisarc rudimentary. Gonophores

in the form of fixed sporosacs borne on blastostyles arising immediately above

the aboral tentacles.

Type species: Branchiocerianthus urceolus Mark, 1898.

One species only from South Africa.

Branchiocerianthus imperator (Allman, 1885)

Fig. 13

Monocaulus imperator Allman, 1885: 753, fig. 265. Allman, 1888: 5, pl. 3.

Branchiocerianthus imperator: Miyajima, 1900: 235, figs 1-2, pls 14-15.

Stechow, 1909: 49, figs 1-4, pl. 7 (figs 1-8). Brattstro6m, 1957: 5. Vervoort, 19665: 99.

Diagnosis. Body very large, over 2 m in length when mature. Hydrocaulus

tubular, narrowest distally and separated from hydranth by a diaphragm and

an annular constriction, widening proximally and ending in a bulbous swelling

bearing anchoring filaments. Base of hydrocaulus and anchoring filaments

covered with thin perisarc. Coelenteron filled with vacuolated endoderm cells

but containing a circle of longitudinal endodermal canals at periphery; these

visible externally as longitudinal striations.

Hydranth disc-shaped, bilaterally symmetrical, especially in young indivi-

duals, with an excentric (‘ventral’) insertion of hydrocaulus and an excentric

(‘dorsal’) hypostome; mouth directed at an angle of 45° to hydrocaulus. Hypo-

stome round in section. Aboral tentacles 100-250 in number and reaching

300 mm, in one, or in two closely alternating whorls, the series broken in the

ventral axis where new tentacles develop. Oral tentacles 48-180 in number and

reaching 55 mm, in several close whorls. Internal cavity divided by a transverse

diaphragm with a circular opening at level of aboral tentacles. Many unbranched

radial canals present immediately above diaphragm and ending blindly at

periphery.

Blastostyles 96-160 in number, in 1-3 whorls, the youngest ventral, branch-

ing 6-8 times, reaching 63 mm, bearing in total up to 600 sporosacs. Each

branch terminating in a battery of nematocysts.

Colour: reddish, varying from pale pink to scarlet and maroon.

Remarks. Since the only material from the South African coast was not in good

condition (Vervoort 19665), the dimensions and tentacle numbers given above

have been taken from Brattstr6m’s summary (1957).

Distribution outside South Africa. Pacific and Indian Oceans, in tropical and

warm temperate waters. Type localities: North Pacific and Japan.

Distribution in South Africa. One record only, off Mocgambique in 730 m.

25/35 (vd)

Ga 4

SG 22

: WA

te of Jee

x fez re F, Ae

ir FI 2 rea! 7 (ag

Noy: ree eS eed

pe RE I

RNS

= = ————_=7 = 2 - ite

eae re

sss

=X,

——

Zz =

—SS—

= —

—

. =

== —S

Fig. 13.

awn from Miyajima (1900). Scale in cm.

30 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Corymorpha M. Sars, 1835

Syn. Steenstrupia Forbes, 1846.

Diagnosis. Hydranth radially symmetrical, with diaphragm and two sets of

filiform tentacles but no radial canals. Hydrocaulus rooted by anchoring fila-

ments. Perisarc a transparent membranous sheath over hydrocaulus. Gono-

phores producing free medusae, borne on blastostyles immediately above aboral

tentacles. Medusa with pointed apex and apical canal, with one moniliform

marginal tentacle.

Type species: Corymorpha nutans M. Sars, 1835.

One species only from South Africa.

Corymorpha sp.

Corymorpha sp. Millard, 1959a: 299.

Diagnosis. Hydranth 14 mm in length, with at least 18 oral tentacles and 18

aboral tentacles. Oral tentacles in two close whorls. Reproduction unknown.

Remarks. Only one infertile specimen has been found, and it is impossible to

delegate it to a species.

Distribution in South Africa. Durban Bay, in mud. 29/31 (s).

Family Tubulariidae

Diagnosis. Athecate, solitary or colonial hydroids with erect stems covered in

perisarc to immediately below the hydranth. Hydranth large, with conical

hypostome and two sets of filiform tentacles (aboral and oral) in adult, the oral

tentacles capitate in the young stages. Gonophores borne on blastostyles which

arise immediately above the aboral tentacles, in the form of fixed sporosacs or

free medusae. Medusa, when present, with four radial canals, gonad completely

surrounding hypostome, one to four perradial marginal tentacles, without ocelli.

An actinula stage present in the life-history.

Introduction. The Tubulariidae are characterized by tall perisarc-covered stems

and large terminal hydranths. In most species the stem is unbranched and con-

nected with other stems only by the reticular hydrorhiza. In Zyzzyzus however,

the hydranths are solitary and in a few species of Tubularia the stem branches

irregularly.

Growth occurs at the distal end of the stem where the newly formed perisarc

is thin and where the coenosarc is dilated. During growth groups of annulations

are formed at this level. These occur quite irregularly in the stem and their

formation is apparently influenced by external factors. At this point, too, the

hydranth may be shed in unfavourable conditions, to be regenerated later from

the living coenosarc..

The histology is comparatively elaborate, second only to that in the Cory-

morphidae. The endoderm of the stem in many species forms longitudinal

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 3]

ridges, visible as striations in external view. These ridges may meet in the centre,

so dividing the coelenteron into longitudinal canals, or may themselves contain

canals. In Zyzzyzus separate ENDODERMAL CANALS are present within the normal

vacuolated endoderm similar to those in the Corymorphidae. The canals com-

municate distally with the gastral cavity of the hydranth.

As in the Corymorphidae the endoderm of the hydranth is thickened round

the base of the body as a DIAPHRAGM or cushion of large vacuolated endoderm

cells bulging towards the centre and constricting the coelenteron. It may be

separated from the endoderm of the aboral tentacles by a lamella of mesogloea.

Similarly the endoderm of the oral tentacles may be separated from that lining

the hypostome by a mesogloeal lamella.

These specializations are associated with the large size of the hydranth.

The gonophores, which are borne on blastostyles arising immediately above

the aboral tentacles, may be in the form of fixed sporosacs (Jubularia and

Zyzzyzus) or become freed as medusae (Ectopleura and Hybocodon). The degree

of development of the sporosac varies between species and sometimes within

the same species. The medusa is little modified and close to the hypothetical

ancestral condition postulated by Rees (1957). In Ectopleura the medusa is

radially symmetrical usually with four marginal tentacles, but in Hybocodon it

is asymmetrical with one or a group of tentacles on one edge and the tentacles

are moniliform.

All the Tubulariidae possess an ACTINULA larva, which is released either by

the sporosac or by the medusa. The eggs are large and yolky and only a few

develop into actinulae at the expense of the others. The actinula possesses one

whorl of filiform aboral tentacles and one whorl of capitate oral tentacles of

which the latter may only develop after release. It does not swam, but sinks

passively to the bottom where it rests mouth upwards on the aboral tentacles.

Growth of the aboral pole produces a short stalk which then achieves attach-

ment to the substratum by the developing perisarc. The young hydranth thus

possesses filiform and capitate tentacles. As development proceeds the oral

tentacles lose their capitula.

Rees (1957) considers that the Tubulariidae evolved from the unspecialized

members of the Corymorphidae by the development of firm perisarc, loss of

anchoring filaments and partial atrophy of the stem canals and diaphragm.

Zyzzyzus represents an intermediate stage in its solitary habit, its soft perisarc

and its endodermal canals. It is included in the Tubulariidae by virtue of the

actinula larva. It possesses rooting processes which, however, are not homo-

logous with the rooting filaments of Corymorphids but are adaptations to a habi-

tat in sponges.

KEY TO GENERA

1. Hydranth solitary, with rooting processes and soft perisarc .. es Zyzzyzus p. 38

— Hydranths usually colonial with a common hydrorhiza, without rooting processes

and with firm perisarc .. ae uae i x8 zn ye ae be D

2. Gonophores in the form of fixed sporosacs .. we ee se Tubularia p. 35

— Gonophores released as free medusae

32 ANNALS OF THE SOUTH AFRICAN MUSEUM

3. Medusa radially symmetrical, with two or four marginal tentacles .. -Ectopleura p. 32

Medusa asymmetrical, with one or a group of marginal tentacles .. Hybocodon p. 32

Genus Ectopleura L. Agassiz, 1862

Diagnosis. Hydranths solitary or colonial, without rooting processes. Hydro-

caulus with firm perisarc. Gonophores released as free-swimming medusae.

Medusa radially symmetrical, with eight exumbrellar tracks of nematocysts.

Type species: Tubularia dumortieri van Beneden, 1844.

One polyp species only from South Africa.

Ectopleura bethae (Warren, 1908)

Fig. 14A—D

Tubularia betheris Warren, 1908: 280, pl. 45 (figs 10-11), pl. 46 (fig. 12).

Ectopleura bethae: Stechow, 1921la: 249. Millard & Bouillon, 1974: 10.

Diagnosis. Hydrorhiza branching, giving rise to unbranched stems up to 33 mm

in length, each bearing a single terminal hydranth. Perisarc firm, irregularly

annulated, especially near base, becoming very thin distally where it terminates

on a dilation of the coenosarc just below the hydranth. Hydranth with 9-17

long aboral tentacles and 10-17 shorter oral tentacles. Oral tentacles capitate

in young hydranth, filiform in mature hydranth but with concentration of nema-

tocysts at distal end.

Blastostyles arising just above aboral tentacles, bearing irregular clusters

of medusa-buds. Medusa-bud with four capitate marginal tentacles, reaching at

least 0,2 mm in diameter before release. Adult medusa unknown.

Distribution outside South Africa. S.E. Madagascar.

Distribution in South Africa. Natal and Inhaca. Type locality: between Park

Rynie and Alexander Junction. 30/30 (1), 26/32

Genus Hybocodon L. Agassiz, 1862

Diagnosis. Hydranths colonial, without rooting processes. Hydrocaulus with

firm perisarc. Gonophores released as free-swimming medusae. Medusa asym-

metrical with margin at oblique angle, with 1-3 marginal tentacles arising from

a single large marginal bulb, the remaining three marginal bulbs rudimentary.

Type species: Hybocodon prolifer L. Agassiz, 1862.

One species only from South Africa.

Hybocodon unicus (Browne, 1902)

Fig. 14E-H

Amphicodon unicus Browne, 1902: 276.

Hybocodon unicus: Browne & Kramp, 1939: 273, pl. 15 (figs 2-3). Kramp, 1959: 87, fig. 35.

Kramp, 1961: 44. Kramp, 1968: 13, fig. 20.

Diagnosis. Hydrorhiza branching within the sponge Hymeniacedon perlevis

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 33

——i_

Ui ca eae es

Fig. 14.

Ectopleura bethae. A, colony; B, mature hydranth with medusa-buds; C, young hydranth

with capitate oral tentacles; D, oldest medusa-bud found.

Hybocodon unicus. E, mature hydranth with medusa-buds; F and G, recently hatched medusae,

G in ventral view; H, nematocysts, from left to right a desmoneme, stenotele, atrichous

isorhiza, microbasic mastigophore.

Scale: A in cm, H in um, the rest in mm/10.

34 ANNALS OF THE SOUTH AFRICAN MUSEUM

(Montagu), giving rise to unbranched stems up to 19 mm in height, each bearing

a single terminal hydranth. Perisarc firm, not annulated, becoming mem-

branous and swollen immediately below hydranth. Hydranth with 12-19 long

aboral tentacles and 15-28 shorter oral tentacles, the latter in two close whorls.

Blastostyles arising just above aboral tentacles, short and branching, bearing

clusters of medusa-buds.

Medusa on release 0,75 mm in height and 0,65 mm in maximum diameter;

with a single marginal tentacle arising from an enlarged marginal bulb; bell

asymmetrical, bulging on side of marginal tentacle and with margin slightly

oblique; the three small marginal bulbs produced over exumbrellar surface for

a short distance; hypostome cylindrical and reaching practically to bell margin;

with four unbranched radial canals; with scattered nematocysts on exumbrellar

surface. Marginal tentacle about 1,3 mm when extended, moniliform, with 26

batteries of nematocysts. Adult medusa (not reported from South Africa) bell-

shaped, 3 mm in height and 2 mm in diameter, with gonad surrounding hypo-

stome from base almost to mouth.

Colour: hydranth transparent with orange-red stomach and hypostome,

sometimes with darker longitudinal streaks on hypostome. Medusa transparent

with orange-yellow hypostome and marginal bulbs.

Nematocysts of four types;

(i) Desmonemes, 4,8 x 3,0 — 6,6 x 5,4 ». Capsule oval, undischarged thread

in two coils.

(ii) Stenoteles, 6,0 x 4,8 — 10,8 x 9,6 uw. Capsule oval. Numerous.

(iii) Microbasic mastigophores, 9,0 x 4,8 — 10,8 x 4,8 ». Capsule elongate-

oval. Butt approximately equal to capsule in length.

(iv) Atrichous isorhizas, 9,0 x 7,2 — 10,2 x 7,2 ». Capsule oval to spherical.

Rare.

Remarks. The absence of nematocyst tracks on the bell of the medusa clearly

distinguishes this species from the well-known H. prolifer. There is also no sign

of the asexual budding so characteristic of the latter species. In the young living

medusa the marginal bulb at the base of the tentacle is single and bean-shaped,

not double as described by Browne & Kramp for H. unicus. The double appear-

ance is assumed on contraction during fixation. I have assigned the species

to H. unicus on the scattered nematocysts, the long hypostome and the distinc-

tive process of the three small marginal bulbs which ‘is attached to and curls over

the margin of the umbrella’ (Browne & Kramp 1939).

This is apparently the first discovery of the hydranth of H. unicus, and the

first record of the genus from South Africa.

Distribution outside South Africa. South Atlantic and India. Type locality:

Falkland Islands.

Distribution in South Africa. Sea Point only, lower littoral under ledges. 33/18

(1)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 35

Genus Tubularia Linnaeus, 1758

Syn. Parypha L. Agassiz, 1862.

Diagnosis. Hydranths colonial, without rooting processes. Hydrocaulus with

firm perisarc. Gonophores in the form of fixed sporosacs, either eumedusoid or

cryptomedusoid.

Type species: Tubularia indivisa Linnaeus, 1758.

KEY TO SPECIES

(Doubtful species not included, for these see p. 38)

1. Stem unbranched. Apical processes of female gonophores laterally compressed T. warreni

— Stem branched. Apical processes of female gonophores conical es ts T. larynx

Tubularia larynx Ellis & Solander, 1786

Fig. 15H-J

Tubularia larynx Ellis & Solander, 1786: 31. Allman, 1872: 406, pl. 21. Pyefinch & Downing,

1949: 21, figs 1-2. Hawes, 1955: 333, figs 1-5. Millard, 1959b: 240. Brinckmann-Voss

UOT Orsi:

Diagnosis. Hydrorhiza a matted reticulum, giving rise to irregularly branched

stems reaching a maximum height of 70 mm, each branch bearing a terminal

hydranth. Perisarc firm, smooth for the most part, but with scattered groups of

shallow annulations, becoming thin distally and terminating below the

hydranth body. Cavity of coenosarc divided longitudinally by 2-4 endodermal

ridges which may meet in the centre and may contain canals. Hydranth with

up to 27 long aboral tentacles and up to 19 shorter oral tentacles.

Blastostyles arising just above aboral tentacles in 1-3 closely alternating

verticils, male and female usually on separate hydranths. Blastostyle branched

or unbranched, bearing the gonophores in clusters. Gonophores without radial

canals or marginal tentacles, oval to spherical, with three or four rounded

tubercles at distal end. Eggs developing into actinulae in situ.

Actinula at liberation with no oral tentacles or with rudiments of 3-5,

with 6-13 long aboral tentacles with swollen tips. Oral tentacles not capitate on

settling. (From the literature, not observed in South Africa.)

Distribution. Cosmopolitan.

Distribution in South Africa. Two records only, one from a ship’s hull in Table

Bay and another from the Agulhas Bank in 126 m. 33/18 (h), 35/20 (d)

Tubularia warreni Ewer, 1953

Frontispiece; Figs 15A—G

Tubularia warreni Ewer, 1953: 351, figs 1-4. Millard, 1959a: 299. Millard, 19595: 240. Millard,

1966a: 435.

?Tubularia sertularellae Stechow 19236: 97. Stechow 1925a: 406.

Diagnosis. Hydrorhiza a matted reticulum giving rise to clusters of unbranched

stems 50-100 mm in length, each bearing a single terminal hydranth. Perisarc

36 ANNALS OF THE SOUTH AFRICAN MUSEUM .

F-J

IR, 115).

Tubularia warreni. A, colony; B, hydranth with female blastostyles; C, newly settled hydranth

with capitate oral tentacles; D, actinula; E, nematocysts, from left to right a desmoneme,

stenotele, heterotrichous anisorhiza, basitrichous isorhiza; F, female gonophore with

crests and protruding spadix; G, male gonophore.

Tubularia larynx. H, female gonophore with tubercles; J, male gonophore.

Scale: A in cm, B in mm, E in pm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 37

firm, smooth for the most part but with scattered groups of 3—7 annulations,

becoming very thin distally where it terminates in a groove round a dilation

of the coenosarc just below the hydranth. Cavity of coenosarc divided longi-

tudinally by two or more endodermal ridges which may contain canals.

Hydranth with up to 31 long aboral tentacles (5 mm or more) and up to 27

shorter oral tentacles (1 mm or more).

Blastostyles arising just above aboral tentacles in two or three closely alter-

nating verticils, 6-12 in each, the oldest ones oral and the youngest aboral,

male and female on separate hydranths. Each blastostyle with a slender axis,

sometimes with a few lateral branches, bearing the gonophores singly or in

clusters. Gonophores without radial canals or marginal tentacles. Male oval

to spherical, normally smooth. Female oval to spherical, with eight laterally

compressed distal crests, containing one or two eggs which develop into actinulae

in situ.

Actinula at liberation normally with eight aboral tentacles and rudiments

of four oral tentacles. Oral tentacles capitate in newly settled hydranth.

Nematocysts of four types:

(i) Desmonemes, 4,2 x 2,4 — 5,4 x 4,2 uw. Capsule oval, discharged thread

with three coils. Numerous.

(ii) Stenoteles, 4,8 x 4,2 — 10,8 x 9,6 u. Capsule oval, butt about two-thirds

length of capsule. Numerous.

(iii) Heterotrichous anisorhizas, 7,8 x 7,2 — 9,6 x 9,6 u. Capsule spherical or

almost so. Thread coiled horizontally when undischarged, armed with spiral

bands of short spines. Rare.*

(iv) Basitrichous isorhizas, 7,8 x 2,4 — 9,0 x 3,0 u. Capsule elongate-oval,

thread coiled longitudinally when undischarged, armed with short spines for

the first part of its length. Rare.

Colour, endoderm of hydranth and spadix of gonophore deep red, ten-

tacles transparent. General impression of living colonies orangy-red.

Variation. The longitudinal endodermal ridges in the stem vary in number from

two to five (though usually two or three) and also in strength. Thus they may

be very low indeed, or they may be high enough to meet in the centre when they

may contain canals.

The oral tentacles of the hydranth are in one verticil in the extended state

but on contraction alternate tentacles get pushed inwards, giving the impression

of two verticils.

The male gonophores, though usually quite smooth, may occasionally

bear four or five rudimentary conical processes at the distal end. In the female

gonophores the distal processes vary in size and may rarely be absent. One or

more may be swollen and distended. The spent female gonophores are elongated-

oval or cylindrical. The spadix of the gonophore usually protrudes through the

aperture in the female, and occasionally in the male.

* This classification is from Ewer (1953). I was not able to verify personally the fact that the

thread tapers.

38 ANNALS OF THE SOUTH AFRICAN MUSEUM

The number of tentacles in the newly released actinula varies from 5 to 12

aboral and up to 6 oral.

Observations on living material. This is one of the hardier species of hydroids,

growing abundantly in dock areas in spite of severe pollution. In the laboratory

thousands of actinulae may be released and become established on the walls

of the tank. The living hydranth readily accepts brine-shrimp larvae which are

stung by the aboral tentacles and transferred to the mouth. The pendulous

blastostyles when at rest hand down between the tentacles to a length of about

10 mm but perform rhythmical contractions, sweeping upwards towards the

mouth.

The newly released actinula rests with the mouth directed upward and the

aboral tentacles held alternately elevated and depressed, the downward-directed

ones supporting it on the substratum. It does not swim but performs slow

exploratory crawling movements. At this stage the slender aboral tentacles are

slightly swollen at the tips and the oral tentacles mere lobes. By the time settling

occurs the aboral part of the body has lengthened to form a short stem covered

with perisarc and the oral tentacles are distinctly capitate and about 0,1 mm in

length. Young hydranths of 2,5 mm have about 12 aboral tentacles and 6

capitate oral tentacles. The capitulum of the oral tentacles is densely covered

with nematocysts. The aboral tentacles have nematocysts scattered along both

oral and aboral surfaces, but the aboral ones are more numerous.

Distribution. Endemic to South Africa. Type locality: Durban harbour.

Distribution in South Africa. Langebaan to Durban, common in dock areas on

pylons and on ships’ hulls. 33/18 (1, h), 34/18 (h), 34/22 (1), 34/23 (h), 29/31 (h)

Doubtful species

Tubularia crocea (L. Agassiz, 1862)

Parypha crocea L. Agassiz, 1862: 249, pls 23—23a.

Tubularia crocea: Brinckmann-Voss, 1970: 28, figs 30-34.

Remarks. Broch (1914) has reported this species from Liideritz Bay in South West

Africa, but the specimens were young and no description was given. The material is

probably referable to T. warreni.

T. crocea differs from T. warreni in details of nematocysts, blastostyles and

actinula.

Genus Zyzzyzus Stechow, 1921

Diagnosis. Hydranths solitary, with rooting hydrorhizal processes. Hydro-

caulus with soft perisarc. Gonophores in the form of fixed sporosacs.

Type species: Tubularia solitaria Warren, 1906a.

One species only from South Africa.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

my 4

=7s

as ES,

YEN

Fig. 16.

Zyzzyzus solitarius. A, hydranth growing in sponge and showing rooting structures; B, mature

hydranth with gonophores and escaping actinulae.

Halocordyle disticha. C, stem; D, part of stem and hydrocladia; E, hydranth with gonophores;

F, gonophore; G, large stenotele.

Scale: C in cm, G in pm, the rest in mm/10.

40 ANNALS OF THE SOUTH AFRICAN MUSEUM

Zyzzyzus solitarius (Warren, 1906)

Fig. 1}6A—B

Tubularia solitaria Warren, 1906b: 83, pls 10-11.

Diagnosis. Hydranths growing in sponges, reaching 13 mm in maximum total

length, and embedded for about half this length. Hydrorhiza and hydrocaulus

not clearly demarcated externally, covered with smooth, soft perisarc which

terminates in a circular groove below hydranth. Hydrorhiza forming slender

supporting ‘rootlets’ and fleshy storage ‘tubers’. Coenosarc of stem with about

16 longitudinal endodermal canals contained within the normal reticular endo-

derm and communicating distally with the gastral cavity of the hydranth.

Hydranth with 15-34 aboral tentacles and 16-21 oral tentacles.

Blastostyles arising just above aboral tentacles, each bearing a cluster of

3-5 gonophores; male and female on same hydranth but on separate blasto-

styles. Gonophores cryptomedusoid, with a subumbrellar cavity opening to

exterior, but no marginal tentacles or radial canals; female containing many

eggs, of which one or two develop into actinulae. Actinula with 9-12 aboral

tentacles.

Colour: hydranth body and gonophores rose-red, hydrocaulus and tentacles

translucent white.

Nematocysts of at least three types:

(i) Large, oval capsules (?stenoteles). 7,2 x 5,9 — 12,1 x 11,6 pu.

(ii) Desmonemes. Small oval capsules. 4,5 x 3,6 — 6,3 x 3,6 pu.

(iii) Bean-shaped capsules (?basitrichous isorhizas). 8,1 x 3,6 — 9,0 x 3,6 u.

Distribution outside South Africa. Cape Verde Islands, Trinidad.

Distribution in South Africa. Saldanha Bay to Mocambique, littoral. Never

common. Type locality: Natal. 33/18 (1), 34/18 (1), 33/27 (1), 30/30 (1), 29/31

(1525/32; 21/35

Family Halocordylidae

Syn. Pennaridae.

Diagnosis. Upright, branching colonies with firm perisarc. Stem pinnate,

bearing alternate hydrocladia. Hydrocladia bearing ramules on upper surface

only. Hydranths borne on the summits of the stem, hydrocladia and ramules.

Hydranth with an aboral whorl of long filiform tentacles and an oral set of

capitate tentacles of which some or all form a whorl around the mouth. Gono-

phores borne on the hydranth above the aboral tentacles.

Introduction. This is one of the few athecate families with an upright stem and a

regular scheme of branching. The arrangement of the side-branches, which arise

alternately and bear the hydranths on short ramules on one surface only, is

similar to that found in the pinnate Plumulariidae, and the same term is used for

them, namely HYDROCLADIA. Firm perisarc clothes the stem and all branches;

it is usually divided into internodes, and annulated in certain areas, particularly

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 4]

in the neighbourhood of the nodes. It terminates in a groove round the base of

each hydranth.

The hydranth is comparatively large and flask-shaped, very similar in

general structure and appearance to that of the Corymorphidae and Tubula-

riidae. Here also there is an aboral whorl of long filiform tentacles, but the oral

tentacles are capitate and in most cases scattered over the whole of the oral

region.

The gonophores are in the form of eumedusae, with four permanently

stunted marginal tentacles and four radial canals. They may or may not have a

short free-swimming existence, and this has in the past been used erroneously

to separate species.

Mammen (1963) described the release of actively pulsating medusoids in

Halocordyle disticha, and these settled on the bottom within a few hours. For

the same species Brinckmann-Voss (1970) stated “The medusae may shed their

sexual products while still attached to the hydranths or they may break free;

they do not swim but sink immediately to the bottom. Liberated and non-

liberated medusae occur on the same colony.’ Since there is no mouth, the

medusae cannot feed and have a limited life.

One genus only.

Genus Halocordyle Allman, 1872

Syn. Pennaria Goldfuss, 1820, non Oken, 1815.

Diagnosis. As for family.

Type species: Globiceps tiarella Ayres, 1854.

One species only in South Africa.

Halocordyle disticha (Goldfuss, 1820)

Fig. 16C-—G

Pennaria disticha Goldfuss, 1820: 89. Brinckmann-Voss, 1970: 40, figs 43-50.

Pennaria australis Bale, 1884: 45.

Halocordyle cooperi Warren, 1906a: 73, pl. 9. Warren, 19076: 209.

Pennaria australis var. cooperi: Warren, 1908: 282.

Pennaria disticha var. australis: Millard, 1959a: 300.

Halocordyle pennaria var. australis: Mammen, 1963: 54, figs 22-24.

Diagnosis. Stem unfascicled, reaching a maximum height of 139 mm, divided

by straight nodes into regular internodes, each bearing a hydrocladium near

distal end, annulated at base and above each node. Hydrocladia alternate, the

two rows in one plane, gently curved, those near the centre of the stem longer

than those at the base and distal end, the longer ones divided by straight nodes

into internodes, each internode bearing a ramule on the upper surface, annulated

at base and above each node. Ramules unsegmented, annulated at least in basal

region.

Hydranths borne on summits of stem, hydrocladia and ramules, with an

aboral whorl of 8-15 long filiform tentacles and an oral set of 8-17 short capitate

42 ANNALS OF THE SOUTH AFRICAN MUSEUM

tentacles wnich may be irregularly scattered or have a roughly verticillate

arrangement.

Gonophores borne on hydranth between the two sets of tentacles, develop-

ing into eumedusae, which may have a short free-living life, male and female on

separate colonies. Gonophores deeper than wide, with four radial canals, four

rudimentary marginal tentacles, a long hypostome and no ocelli.

Nematocysts of at least three kinds:

(i) Stenoteles, large ones (to 47 x 25 ») on capitate tentacles, and small ones

(8 x 5 — 14 x 10 z) on all tentacles, abundant.

(ii) Desmonemes, 6,5 x 5,5 », on all tentacles.

(iii) ?Microbasic mastigophores, 11,5 x 5 », on all tentacles, scarce.

Colour (preserved): stem dark-brown to black, becoming lighter towards

the extremities which are transparent, hydranths reddish, gonophores with red-

dish longitudinal stripes.

Variation. The amount of annulation on the stem and branches has been shown

by many authors to be variable, so that it is probably no longer correct to retain

var. australis (Bale 1884), which is distinguished mainly by the paucity of

annulations on the hydranth-bearing ramules.

The stem may have as many as 20 annulations at the base and up to 11

above each node, though more commonly four or five. The hydrocladia may

have true annulations or-spiral ridges. The ramules usually have one or two

rings at the base, but there may be a large number, and there may also be a

group at the distal end. Additional groups of annulations may occur anywhere

on the stem or its branches. The South African material can be assigned to var.

australis if this should be retained.

Distribution. Circumglobal in tropical and subtropical waters.

Distribution in South Africa. East coast, from just south of Durban to Mocam-

bique, lower littoral region to 3 m, and on ships’ hulls. 30/30 (1), 29/31 (1, h),

27/32 CO) 26/32 (1); 24135 (S)a23/ 31a

Family Myriothelidae

Diagnosis. Large solitary hydranths attached to substratum by special perisarcal

anchoring structures. Tentacles all capitate, numerous, scattered. Gonophores

borne either on special blastostyles or direct on hydranth body.

Introduction. The Myriothelidae is a family of solitary hydranths in which some

species have attained great size with accompanying elaborations of internal

structure, a process paralleling that in the Corymorphidae. Thus, the endoderm

is thrown into villi projecting into the coelenteron and the mesogloeal layer is

thickened and bears lamellae on its outer surface supporting the longitudinal

muscles (Fig. 18E). These features occur to a greater or lesser extent in the larger

species and culminate in the giant Myriothela penola which can reach a length

of 850 mm and has about 330 000 body tentacles (Manton 1940).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 43

The body is normally cylindrical but can perform active contractile move-

ments involving changes of shape. The distal and major part is thickly covered

with tentacles, while the base is permanently attached to the substratum. A

perisarcal sheath covers the basal region in Arum and Monocoryne, but in

Myriothela the body is entirely naked, and perisarc is limited to the adhesive

structures. The latter are processes of the body and may be (1) tubular with

sucker-like distal ends, e.g. Arum cocksi, (2) tentacle-like, e.g. Myriothela

phrygia and M. capensis, or (3) root-like, e.g. Monocoryne gigantea. In the

first and second types the processes are fastened to the substratum by chitinoid

ATTACHMENT DISCS which are in continuity with the mesogloea, and in Myrio-

thela capensis the underlying ectoderm disappears. If torn away these discs can-

not be reattached, although new adhesive structures may be formed (Manton

1941).

The tentacles are always capitate; single and scattered in Arum and Myrio-

thela, but attached to one another in groups of three or four in Monocoryne.

Each tentacle contains a lumen separated from that of the main body cavity,

and the mesogloea often expands in the capitulum to form a thick apical pad

(Fig. 18C). In Myriothela new tentacles are continually formed at the oral end,

while the basal ones are progressively reduced and absorbed, and this is probably

also the case in the other genera.

Reproduction, so far as is known, is always by means of fixed sporosacs,

and the eggs, at any rate in Myriothela, develop into actinulae. The gonophores

may be borne directly on the body (Monocoryne) or may arise from special

blastostyles (Myriothela and Arum). The blastostyles arise from a budding zone

between the attachment processes and the lowest body tentacles; they may be

branched or unbranched and with or without capitate tentacles similar to those

of the body.

KEY TO GENERA

[Genera not represented in South Africa are vracketed]

1. Tentacles grouped .. “ee ae a ad ae Bs .. Monocoryne p. 43

Tentacles single .. ape a, ae ae Pe ce ee re a Z

2. Proximal end of hydranth naked; perisarc present only on tips of anchoring fila-

ments tos LA Ws a ay fs as an .. Myriothela p. 45

— Proximal end of hydranth and anchoring filaments sheathed in perisarc [Arum]

Genus Monocoryne Broch, 1909

Syn. Symplectanea Fraser, 1941.

Diagnosis. Proximal end of hydranth and anchoring filaments surrounded by a

perisarcal sheath. Distal end of hydranth bearing tentacles attached to one

another in groups. No blastostyles; gonophores borne on body, in the form of

fixed sporosacs.

Type species: Coryne gigantea Bonnevie, 1898.

One species only from South Africa.

44 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 17.

Monocoryne minor. A, complete individual; B, a typical group of four tentacles.

Myriothela tentaculata. C, nematocysts, from left to right: large desmoneme, small desmoneme,

heteroneme, atrichous isorhiza, stenotele.

Myriothela capensis. D, nematocysts, from left to right: undischarged and discharged large

desmoneme, small desmoneme, heteroneme, ?atrichous isorhiza, stenotele, ?7haploneme.

Scale: C and D in pm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 45

Monocoryne minor Millard, 1966

Fig. 17A-B

Monocoryne minor Millard, 1966a: 435, fig. 1.

Diagnosis. Hydranth cylindrical, about 5 mm in length. Basal part (one-quarter)

sheathed in transparent perisarc and giving rise to anchoring filaments. Distal

part (three-quarters) naked, bearing about 110 capitate tentacles usually in

groups of two, three or four united at the base; usually one tentacle of a group

longer than the others.

Gonophores (?male) scattered on distal part of body, pear-shaped, reaching

a diameter of 0,3 mm.

Nematocysts of at least three kinds:

(i) Desmonemes, 9,0 x 6,3 — 13,5 x 10,8 ». Capsule oval, thread in about two

coils. Abundant.

(ii) Stenoteles, 15,3 x 13,0 — 18,0 x 15,3 ». Capsule oval, butt about half

length of capsule. Fairly common.

(i111) Undetermined heteronemes, 16,2 <x 6,3 — 18,9 x 7,6 ». Capsule elongated,

butt about 2 length of capsule. Rare.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only record: Agulhas Bank in

77 m. 34/25 (s)

Genus Myriothela M. Sars, 1851

Syn. Candelabrum de Blainville, 1830 (nomen oblitum).

Diagnosis. Proximal end of hydranth without perisarc, bearing adhesive pro-

cesses with perisarc only at the tips. Distal end of hydranth bearing separate,

scattered tentacles. Gonophores in the form of fixed sporosacs, borne on blasto-

styles arising below the area of body tentacles. An actinula stage in the life

history.

Type species: Lucernaria phrygia Fabricius, 1780.

KEY TO SPECIES

1. Blastostyles about 1,5 mm long, with about 5 capitate tentacles at distal end M. capensis

— Blastostyles long and tendril-like, up to 20 mm, with over 25 scattered capitate

tentacles .. Ne ue fs vi he Ae ae oe M. tentaculata

Myriothela capensis Manton, 1940

Fig. 17D, 18A, F-G

Mpyriothela capensis Manton, 1940: 276, figs 7, 8b, 9, pl. 1 (figs 12-13), pl. 3 (fig. 27). Millard,

1966a: 437.

Diagnosis. Hydranth cylindrical, naked, reaching 25 mm in length, usually

attached to weed. Basal part of body (one-tenth) bearing 20-30 adhesive pro-

cesses capped by chitinoid discs. Distal part (nine-tenths) bearing 400-600

densely packed capitate tentacles.

46 ANNALS OF THE SOUTH AFRICAN MUSEUM

Blastostyles arising from basal part of body (above adhesive processes)

in a single whorl of about 20, unbranched, reaching 4 mm in length, bearing up

to nine gonophores in proximal region, the oldest distal, and 4~7 capitate

tentacles in distal region, of which some may be adhesive. Male and female on

separate hydranths. Female gonophore sessile, spherical, reaching 0,9 mm in

diameter, releasing up to three actinulae.

Nematocysts of possibly five types:

(i) Desmonemes, 7,8 x 5,4 — 16,8 x 12,6 ». Capsule oval, thread in one to

three coils.

(ii) Stenoteles, 9,9 x 8,1 — 11,4 x 7,2 uw. Capsule oval, butt just over half

length of capsule.

(iii) Undetermined heteronemes, 11,7 x 3,6 — 19,2 x 6,0 uw. Capsule elongated,

butt almost entire length of capsule.

(iv) Undetermined haplonemes, 10,8 < 9,9 ». Capsule wide-oval.

(v) ?Atrichous isorhizas, 18,0 x 6,0 ». Capsule elongated, no butt, thread

coiled mainly in longitudinal plane. Not always present.

Colour variable. In one individual the capitula of most of the body tentacles

were purple-brown, with amongst them white tentacles fewer in number and

in roughly longitudinal bands; the gonophores had about seven longitudinal

purple-brown stripes and two apical rings; the rest of the body was creamy white.

In another individual the capitula of the body tentacles and tips of the gono-

phores were bright magenta, fading to pink on the stalks of the tentacles and

white on the base of the body. A third individual was uniformly pink.

Variation. Various algae are used as hosts, including Ecklonia maxima (Osbeck)

and Codium sp. It has also been found attached to a crustacean appendage and

inside an empty limpet shell.

Distribution. Endemic to South Africa.

Distribution in South Africa. Liideritz Bay to East London, littoral to 27 m.

Type locality: Aquarium rocks, East London. 26/15 (1), 32/18 (s), 34/18 C., s),

35) 27a (b)

Myriothela tentaculata Millard, 1966

Fig. 17C, 18B-E

Mpyriothela tentaculata Millard, 1966a: 437, fig. 2.

Diagnosis. Hydranth cylindrical, naked, reaching 31 mm in length, attached to

encrusting polyzoans. Basal part of body (two-fifths) bearing about nine short,

adhesive processes capped by chitinoid discs. Distal part (three-fifths) bearing

densely packed capitate tentacles.

Blastostyles arising from basal part of body (above adhesive processes)

in a single whorl of 17; unbranched, long and tapering and generally coiled,

reaching 20 mm, bearing 4-8 gonophores in the proximal region, the oldest

distal, and over 25 capitate tentacles on distal region and scattered amongst the

gonophores. Tentacles not adhesive and resembling boot-buttons. Male gono-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 47

GOR

Oe Co Oo

<COYC ie)

Fig. 18.

Myriothela capensis. A, complete individual extended; F, male blastostyle, contracted;

G, female blastostyle, extended.

Myriothela tentaculata. B, individual attached to polyzoan; C, |.s. body tentacle; D, ls.

blastostyle tentacle; E, t.s. body wall including origins of two tentacles on lower side of

diagram.

Abbreviations: e: ectoderm; m: mesogloea; ml: mesogloeal lamella; mp: apical pad of

mesogloea; m: nematocysts; v: endodermal villi.

Scale: A, B, F and G in mm, C-E in mm/10.

48 ANNALS OF THE SOUTH AFRICAN MUSEUM

phores spherical, reaching 2 mm in diameter, pedicellate. Female gonophores

unknown.

Nematocysts of four types:

(i) Desmonemes, 10,2 x 7,2 — 18,0 x 14,4 uw. Capsule oval, thread in two or

three coils.

(ii) Stenoteles, 14,4 x 10,8 ». Capsule oval, butt over half length of capsule.

(iii) Undetermined heteronemes, 44,1 x 8,1 — 45,9 x 8,1 ». Capsule banana-

shaped, butt almost entire length of capsule.

(iv) Atrichous isorhizas, 15,3 x 4,0 — 19,8 x 7,2 u. Capsule elongate-oval.

Variation. The tentacles are well developed at the distal end of the body, with

large capitula and long stalks, but become progressively reduced as they

approach the blastostyle region.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only record: off Slangkop on the

west coast of the Cape Peninsula, in 43 m. 34/18 (s)

Family Corynidae

Diagnosis. Colonial hydroids with erect stems and firm perisarc. Hydranth

with conical hypostome, with capitate tentacles only or with short filiform ten-

tacles below the capitate ones. Gonophores borne on or below hydranth body,

in the form of fixed sporosacs or free medusae. Medusa, when present, with

simple circular mouth, four radial canals, gonads completely surrounding

stomach, 2-4 hollow marginal tentacles and ocelli.

Introduction. In this family the tentacles of the hydranth are very varied in

structure and arrangement so that allocation into genera is difficult. All possess

capitate tentacles, and these may be arranged in definite whorls located on

definite regions of the body (two well-separated whorls in Bicorona and Dicy-

clocoryne, one aboral whorl in Sphaerocoryne, one oral whorl in some species

of Dipurena) or they may be spread over the whole of the body. In the latter

case there are usually three or four tentacles grouped around the mouth and

the rest of the tentacles may show an indistinct whorling, but for ease of

terminology they are here referred to as ‘scattered’.

In addition to the capitate tentacles some species possess an additional

whorl of vestigial filiform tentacles round the base of the hydranth. The presence

or absence of filiform tentacles has in the past been used as a diagnostic

generic character, but it has been shown that they may occur in some hydranths

of a colony and not in others, or that they may occur in primary and secondary

hydranths but not in tertiary ones (Rees 1957; Brinckmann-Voss 1970). I have,

therefore, followed Brinckmann-Voss in uniting Stauridiosarsia with Sarsia,

and Staurocoryne with Coryne. Rees (1957) suggests that there has been a general

trend amongst the Corynidae towards the loss of filiform tentacles and the addi-

tion of whorls of short capitate tentacles.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 49

Free-swimming medusae are formed in Dicyclocoryne, Dipurena, Sarsia

and Sphaerocoryne. In some cases differentiation of the medusa generation

appears to have advanced further than the hydranth generation. For instance

the hydranths of Dipurena and Sarsia are almost identical, but their medusae

are distinct, and in this case I prefer to retain the two genera and have not

united them as was done by Brinckmann-Voss. Furthermore the hydranth of

Dipurena reesi is very similar to that of Cladonema radiatum whose medusa

belongs to a completely different family.

An actinula larva occurs in the genus Actigia Stechow, 1921, a genus which

can probably be included in Coryne, and actinula-like buds have been shown by

Rees (1957) to occur in Sarsia tubulosa.

KEY TO GENERA

[Genera in which the hydranth generation is unknown in South Africa are bracketed]

1. Capitate tentacles limited to one whorl or two closely alternating whorls near base

of hydranth ae Ay aie a ne 255 as ae p. 5

— Capitate tentacles not as above a

2. Capitate tentacles in two distinct and widely separated whorls, one oral oa one

aboral ae 3

— Capitate tentacles scattered or indistinctly whorled over whole body, or limited to

an oral whorl ce i a ate oe ae aie ae a 4

3. Producing fixed sporosacs ae f A on os : Bicorona p. 49

— Producing free medusae .. ay ne ae x Be Weal

4. Producing fixed sporosacs a oe mn ate es - Coryne p. 51

— Producing free medusae ; : oe oe 5

5. Medusa with undivided gonad .. ve Be Sarsia p. 52

— Medusa with gonad in two or more rings round qomads ges .. [Dipurena]

Genus Bicorona Millard, 1966

Diagnosis. Colonies with erect, branched stems. Mature hydranth with two

widely separated whorls of capitate tentacles, one oral and one aboral. No

filiform tentacles. Gonophores in the form of fixed sporosacs borne on the body

of the hydranth.

Type species: Bicorona elegans Millard, 1966.

One species only.

Bicorona elegans Millard, 1966

Frontispiece; Fig. 19A—E

Bicorona elegans Millard, 1966a: 441, fig. 3.

Diagnosis. Stem unfascicled, reaching 58 mm in height, giving rise to alternate

branches which may rebranch in a similar manner. Perisarc closely annulated

throughout except for a smooth area on the origin of each branch, terminating

as a gelatinous layer over the base of each hydranth.

Hydranths borne on summits of stem and branches, 1-2 mm in length,

with an aboral whorl of 10-21 capitate tentacles and an oral whorl of 4-7

50 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 19.

Bicorona elegans. A, stems; B, mature hydranth bearing gonophores; C and D, young

hydranths; E, nematocysts: large and small stenoteles.

Coryne ?pusilla. F and G, stems, G producing regeneration bodies.

Scale: A in cm, E in mm/100, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 51

shorter capitate tentacles. Aboral tentacles held alternately elevated and

depressed in life, oral tentacles held erect. Aboral tentacles of young hydranth

in three alternating verticils.

Gonophores borne on about seven short blastostyles arising immediately

above aboral tentacles, 2-4 on each, oval to spherical, in the form of fixed

sporosacs, male and female on separate colonies. Female gonophore reaching

0,4 mm in diameter, containing 29-84 small eggs. Male gonophore reaching 0,6

mm in diameter.

Nematocysts: stenoteles, 13,5 x 7,2 — 26,1 x 17,1 ». Capsule oval.

Colour: colony a rich plum-colour, shading to dark-red on the stems and

cose-pink on the hydranth tentacles.

Distribution. Endemic to South Africa.

Distribution in South Africa. Saldanha Bay, west coast of Cape Peninsula, East

London, littoral. Type locality: Saldanha Bay. 33/18 (1), 34/18 (1), 33/27 (1)

Genus Coryne Gaertner, 1774

Syn. Staurocoryne Rotch, 1872.

Syncoryna Ehrenberg, 1834.

Diagnosis. Hydranth with capitate tentacles scattered, or in rough whorls,

over whole of body, and sometimes with a whorl of short filiform tentacles

below them. Gonophores in the form of fixed sporosacs borne on the hydranth.

Type species: Coryne pusilla Gaertner, 1774.

One species only from South Africa.

Coryne pusilla Gaertner, 1774

Fig. 19F-G

Coryne pusilla Gaertner, 1774: 40, pl. 4 (fig. 8). Hincks, 1868: 39, pl. 7 (fig. 1). Warren, 1908:

289, fig. 4. Brinckmann-Voss, 1970: 51, fig. 57. ?Millard & Bouillon, 1974: 13, fig. 1B, C.

Diagnosis. Stem unfascicled, reaching about 13 mm in height, branching irreg-

ularly. Perisarc strongly annulated at least in distal part, annulations often

becoming irregular and indistinct in lower part, terminating on base of hydranth

but not expanded.

Hydranth spindle-shaped, about 1,3 mm in length, with 20-30 scattered

capitate tentacles.

Gonophores borne on hydranth amongst the tentacles, in the form of fixed

sporosacs.

Nematocysts: stenoteles, 8,4 x 4,8 — 16,7 x 11,2 np.

Variation. A dwarf form of Coryne also occurs, which reaches about half the

size. The hydranth has 10-19 tentacles and is 0,4-0,8 mm in length. Since

32 ANNALS OF THE SOUTH AFRICAN MUSEUM

gonophores have not been recorded for this form it is not certain that it is the

same species. Such records are indicated with a query below.

The dwarf form may produce ‘regeneration bodies’, which are budded off

from the tips of branches. In appearance they resemble planula larvae; they

represent a form of asexual reproduction.

Distribution outside South Africa. Common in the North Atlantic from the

Arctic to the Mediterranean. Scattered records, some of them doubtful, from

the Indian Ocean (Madagascar and Kerguelen) and the Pacific (Japan).

Distribution in South Africa. Natal and ?Inhaca, littoral. 30/30 (1), 226/32 (1)

Genus Sarsia Lesson, 1843

Syn. Stauridiosarsia Mayer, 1910.

Diagnosis. Hydranth with capitate tentacles scattered, or in rough whorls,

over whole of body, and sometimes with a whorl of short filiform tentacles

below them. Gonophores borne on body of hydranth, developing into medusae.

Medusa with gonad forming a continuous ring around stomach.

Type species: Oceania tubulosa M. Sars, 1835.

One species only from South Africa.

Sarsia eximia (Allman, 1859)

Fig. 20A-D

Coryne eximia Allman, 1859: 141.

Syncoryne eximia: Allman, 1872: 282, pl. 5. Hincks, 1868: 50, pl. 9 (fig. 2).

Sarsia eximia: Russell, 1938: 150, figs 8-12. Russell, 1953: 50, figs 17A, 18A—B, pl. 2 (fig. 3).

Millard, 1959b: 241. Kramp, 1961: 27. Millard, 1966a: 444.

Diagnosis. Stem erect, reaching a height of 53 mm, unfascicled, branching pro-

fusely and irregularly, though final branches with a tendency to unilateral

arrangement. Perisarc mainly smooth but annulated on base of stem, on origin of

branches and sometimes for entire length on smallest branches; terminating as

a very delicate layer below the first tentacles of the hydranth.

Hydranth tubular, reaching 1,7 mm in height, with 15—26 scattered capitate

tentacles, four or five of which form a verticil round the mouth; bearing

medusa-buds amongst the tentacles.

Medusa at liberation reaching 1 mm in height and diameter, with thin

jelly, four moniliform marginal tentacles, four black ocelli on the marginal

bulbs and scattered nematocysts on the bell. Mature medusa (not recorded from

South Africa) reaching 3-4 mm in height and 2 mm in diameter, with four per-

radial marginal tentacles and four ocelli. Hypostome not extending beyond mar-

gin of bell, female with a few large eggs.

Nematocysts of hydranth: stenoteles of variable size, 5,4 x 4,0 — 17,1 x

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 53

¥.

Fig. 20.

Sarsia eximia. A, hydranth with medusa-buds; B, colony; C, newly liberated medusa;

D, nematocysts, from left to right a stenotele from the hydranth, an undischarged and

discharged desmoneme from the medusa.

Sphaerocoryne bedoti. E, hydranth with medusa-buds, redrawn from Warren (1908, as

Clavatella multitentaculata).

Asyncoryne ryniensis. F, hydranth with medusa-buds, redrawn from Warren (1908).

Scale: B in mm, D in pm, the rest in mm/10.

54 ANNALS OF THE SOUTH AFRICAN MUSEUM

12,6 ». Butt length approximately equal to capsule length and bearing three

Jarge spines and three spiral rows of small spines on its distal half.

Nematocysts of medusa of two types:

(i) Stenoteles, 8,1 x 5,4 — 10,4 x 8,1 ». Structure as in hydranth.

(ii) Desmonemes, 6,3 x 3,2 — 9,0 x 4,5 pu.

Observations on living material. This species releases abundant medusae during

the summer months of December to February and even as late as April; these

live well in the laboratory during their early stages, but have not been reared to

maturity in this country. Nor have fully mature medusae been reported from the

plankton. Newly hatched medusae have alternate swimming and resting phases.

They swim with rhythmical contractions of the bell and velum, holding the

tentacles in a contracted state. During resting the bell relaxes and the tentacles

extend to about double the height of the bell, trailing in the water in the ‘fish-

ing’ position. The tentacles bear about 20 nematocyst batteries, of which the

terminal one is the largest. The largest size reached in the laboratory is 2,8 x

2,7 mm, with no gonads visible.

Colour: hydranth orange-pink, medusa transparent with reddish-brown

marginal bulbs and hypostome.

Distribution outside South Africa. North Atlantic from America to Europe and

from Iceland to France, Mediterranean, west coast of North America, New

Zealand. Medusae also from Brazil, Valparaiso and the N.W. Pacific. Type

locality: Great Britain.

Distribution in South Africa. Common in the environs of Cape Town, on ships’

hulls, pylons and floating objects, and also on rocky shores. Certainly present

from Liideritz Bay in South West Africa to Llandudno on the west coast of the

Cape Peninsula, with doubtful (infertile) records from False Bay, the south coast

and Inhaca in Mocambique. 26/15 (1), 33/18 (1, h), 34/18 (1), 234/22 (1), 234/23

(1), 226/32 (1)

Genus Sphaerocoryne Pictet, 1893

Diagnosis. Hydranth with capitate tentacles in one whorl or two closely alter-

nating whorls round lower part of body. No filiform tentacles. Gonophores

borne on body of hydranth, developing into medusae. Adult medusa unknown.

Type species: Sphaerocoryne bedoti Pictet, 1893.

One species only in South Africa.

Sphaerocoryne bedoti Pictet, 1893

Fig. 20E

Sphaerocoryne bedoti Pictet, 1893: 10, pl. 1 (figs 5-6). Mammen, 1963: 48, figs 16-18. Millard

& Bouillon, 1974: 13, fig. 1A.

Clavatella multitentaculata Warren 1908: 278, pl. 45 (figs 7-9).

Sphaerocoryne multitentaculata: Yamada & Konno 1973: 103, figs 1-3.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 55

Diagnosis. Hydrorhiza embedded in sponge, ramifying, giving rise to solitary

hydranths on long stems with a maximum total height of 13 mm. Pedicel with

smooth perisarc terminating just above a groove below hydranth, increasing

in diameter from base to distal end.

Hydranth pear-shaped, reaching a maximum height of 0,8 mm, with 15-35

solid capitate tentacles arranged in two closely alternating whorls on lower part

of body. No oral tentacles. Hypostome conical.

Gonophores borne in clusters on hydranth body immediately above ten-

tacles, in the form of medusa-buds.

Medusa (not recorded from South Africa) on liberation nearly spherical,

0,5-0,6 mm in diameter, with four marginal bulbs. On maturity with four

marginal tentacles bearing spirally arranged clusters .of nematocysts and four

abaxial ocelli; male nearly ovoid, reaching 3,5 mm in height and 3,0 mm in

diameter; female deeper, reaching 4,5 mm in height and 3,0 mm in diameter.

(From Yamada & Konno.)

Colour: chalky white round mouth, below this a band of lemon-yellow

and below this an irregular band of bright red just above the tentacles. (From

Warren.)

Nematocysts: stenoteles and desmonemes in polyp; stenoteles, desmo-

nemes and basitrichous haplonemes in medusa.

Distribution outside South Africa. India (type locality), Queensland, Madagascar,

Japan.

Distribution in South Africa. Natal and Mocgambique, intertidal. Rare. 30/30

(1), 21/35

Family Cladonemidae

Diagnosis. Hydranths colonial, arising directly from a creeping stolon, with or

without perisarc, with an oral whorl of capitate tentacles, with or without an

aboral whorl of short filiform tentacles. Gonophores borne on hydranth body,

producing free medusae. Medusa with simple, tubular mouth which may be

armed with nematocyst clusters; with a variable number of radial canals,

simple or branched. Marginal tentacles hollow, branched, one branch with

one or more adhesive discs. Ocelli present.

Introduction. This family includes the three genera Cladonema, Eleutheria and

Staurocladia. Most modern authors divide these genera between the two families

Cladonemidae (Cl/adonema) and Eleutheriidae (Eleutheria and Staurocladia),

but I have followed Naumov (1960) and Prévot (1959) in maintaining that both

hydranth and medusa generations have too many characters in common to merit

distinction at the familial level.

The hydranth is very simple and resembles some of the more primitive

Corynidae. The perisarc is poorly developed, if present, and the hydranth has

56 ANNALS OF THE SOUTH AFRICAN MUSEUM

an oral whorl of a few capitate tentacles and sometimes an aboral whorl of

short filiform tentacles as well.

The medusa generation, on the other hand, is highly evolved and specialized.

It has received more attention than usual in this monograph because the single

South African species (of Staurocladia) has a creeping habit and is commonly

encountered on weed in rock-pools and shallow bays. Eleutheria also has a

creeping medusa, but in Cladonema the medusa normally swims and only comes

to rest as a temporary measure.

Creeping is made possible by the presence of adhesive discs on the marginal

tentacles. The marginal tentacles, which are usually numerous, branch, several

times in Cladonema, only once in Eleutheria and Staurocladia. The oral branch

bears the adhesive discs and the aboral branch bears one or more clusters of

nematocysts resembling the capitula of capitate tentacles.

The mouth of the medusa is armed with nematocyst clusters resembling

capitate tentacles in Cladonema. This armature is normally absent in Eleutheria

and Staurocladia, but Ralph (1947) has found vestigial clusters in Staurocladia

vallentini in New Zealand. Eleutheria and Staurocladia possess a thickened ring

of nematocysts round the umbrella margin.

Asexual reproduction by the production of buds or vertical fission of the

medusa has been reported in several species.

The medusae may be dioecious or hermaphrodite. In Eleutheria the fer-

tilized eggs are retained in a brood-pouch, situated above the stomach, to the

planula stage.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Marginal tentacles of medusa with several branches .. ae .. [Cladonema]

— Marginal tentacles of medusa bifurcating ; D

2. Hydranth with capitate tentacles only. Medusa sth Apenal branch of ‘ones

bearing one nematocyst cluster only .. .. [Eleutheria]

— Hydranth with capitate and filiform tentacles. Miedned ih aboral branch of ten-

tacle bearing more than one nematocyst cluster he By .. Staurocladia p. 56

Genus Staurocladia Hartlaub, 1917

Syn. Cnidonema Gilchrist, 1919.

Diagnosis. Hydranth with both filiform and capitate tentacles. Medusa of creep-

ing habit, without nematocyst armature on mouth, with thick ring of nemato-

cysts around margin, without brood-pouch; gonads well developed, either in

ectodermal pockets or completely surrounding stomach; sexes separate; with

six Or more radial canals; with numerous bifurcated marginal tentacles, the oral

branch with a terminal adhesive disc, the aboral branch with several clusters of

nematocysts.

Type species: Eleutheria vallentini Browne, 1902.

One species only from South Africa.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 57

Staurocladia vallentini (Browne, 1902)

Fig. 23D-G

Eleutheria vallentini Browne, 1902: 279.

Cnidonema capensis Gilchrist, 1919: 509, pl. 30. .

Staurocladia vallentini: Browne & Kramp, 1939: 274, pl. 14 (figs 3-4), pl. 15 (fig. 4), pl. 19

(fig. 2). Millard, 1966a: 444.

Cnidonema vallentini: Ralph, 1947: 414, fig. 1, pl. 35.

Diagnosis. Hydranth borne on a slender hydrocaulus arising direct from a

creeping hydrorhyza, minute, reaching 1,5 mm in length, slender at base and

increasing in diameter distally, with 3-4 capitate oral tentacles and 4—6 filiform

aboral tentacles. Hydrocaulus reaching 2 mm in length, covered with thin peri-

sarc. Medusa-buds borne at or slightly above level of aboral tentacles, with about

six bifurcated tentacles at liberation, the aboral branch with one nematocyst

cluster.

Mature medusa about twice as wide as deep, reaching 3,3 mm in diameter.

Marginal tentacles increasing in number with age and reaching about 40 in

large individuals, oral branch bearing a single terminal adhesive disc, aboral

branch bearing median, crescent-shaped clusters of nematocysts: one terminal,

2-4 abaxial and sometimes one adaxial. Radial canals six, unbranched. Stomach

with six pouches. Gonads above and around stomach, in six ectodermal pockets.

Asexual reproduction common in young medusae.

Nematocysts of two types:

i) Desmonemes, 9,6 x 4,2 pu.

(ii) Stenoteles, 10,8 <x 6,6 — 18,6 x 12,6 pu.

Colour: Hydranth transparent with reddish endoderm. Medusa mostly

transparent, with reddish-brown circular canal and stomach, dark brown to

black ocelli, and opaque, white radiating lines on upper surface.

Variation and remarks. The arrangement of the nematocyst clusters on the

aboral branch of the medusa tentacle is variable. They are, however, always

median in position, and there is always one terminal one. In most populations

all the remaining clusters are abaxial, but I have seen one population in which

they are alternately abaxial and adaxial as described by Gilchrist. Occasionally

there is a cluster on the abaxial side of the tentacle before the bifurcation.

When the medusa is at rest the adhesive discs are attached to the sub-

stratum and the aboral branches of the tentacles elevated. Creeping is accom-

plished by releasing and re-attaching the discs.

Distribution outside South Africa. Falkland Islands (type locality). Australasia.

?Bermuda.

Distribution in South Africa. Liideritz Bay to False Bay. Medusa locally com-

mon on weed at certain seasons, hydranth recorded only once. Hydranth:

34/18 (1). Medusa: 26/15 (1), 33/18 (1), 34/18 (1).

58 ANNALS OF THE SOUTH AFRICAN MUSEUM

Family Solanderiidae

Diagnosis. Upright, branching colonies with an internal skeleton of chitinous

trabeculae which may protrude through the surface as spines or hydrophores.

Hydranths all alike, cylindrical, with scattered capitate tentacles, of which four

or five usually form a whorl around the mouth. Gonophores, where known, in

the form of fixed sporosacs borne directly on coenosarc.

Introduction. The Solanderiidae is one of the few groups of hydroids to possess

an internal skeleton. This skeleton consists of an anastomosing meshwork of

chitinous TRABECULAE which rises from an incrusting base to form an erect and

elaborately branching stem. The entire colony is covered externally, and per-

meated internally, by living coenosarc, which bears the hydranths and gono-

phores on the surface. Though the skeleton is morphologically internal, it is

not ‘mesogloeal’, and has been shown by Vervoort (1966a) to be ectodermal in

origin and everywhere covered or lined by cellular ectoderm. The condition is

comparable with that in some Hydractiniidae (Hydractinia) and Zancleidae

(Rosalinda and Teissiera).

The hydranths are borne over the whole surface of the stem and branches

and are usually supported by bracket-like HYDROPHORES arising from the tra-

beculae of the skeleton and projecting through the superficial coenosarc. These

hydrophores may be scoop-shaped, bilobed, or double and with two lateral

triangular shields. Spiny or spatulate projections, the latter resembling abortive

hydrophores, may also occur in some species.

The highly extensile hydranths are very homogeneous and there is no

approach to polymorphism. The shortly stalked capitate tentacles are arranged

irregularly over the body, although a group of four or five usually forms a whorl

around the mouth.

The gonophores, where known, are borne directly on the coenosarc.

They are stalked eumedusoids without marginal tentacles, but sometimes with

radial canals. No free-swimming life has been observed. Colonies are dioecious,

though no differences in structure between male and female colonies have been

seen.

One genus only.

Genus Solanderia Duchassaing & Michelin, 1846

Syn. Ceratella Gray, 1868.

Dehitella Gray, 1868.

Dendrocoryne Inaba, 1892.

Spongiocladium Jaderholm, 1896.

Diagnosis. Colony erect and strongly branched, generally fan-shaped and with

the ramifications more or less in one plane, arising from a flattened base of

hydrorhizal fibres. Skeleton usually forming bracket-like hydrophores which

support the hydranths. Gonophores borne direct on the coenosarc.

Type species: Solanderia gracilis Duchassaing & Michelin, 1846.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 59

KEY TO SPECIES

(Doubtful species not included. For these see p. 61)

1. Hydrophores eae ben bilobed or double. ce. with about 15

tentacles ae bie S. procumbens

— Hydrophore always double: one half on act side of hydrant. Hydranth with up to

33 tentacless .. 2, vs Ae a ; re .. S&. minima

Solanderia minima (Hickson, 1903)

Fig. 21C-E

Ceratella minima Hickson, 1903: 113, pl. 13.

Solanderia minima: Vervoort, 1967: 25, fig. 2, pl. 3 (figs 3-4). Millard & Bouillon, 1973: 16,

fig. 2A-B, pl. 1.

Diagnosis. Colony fan-shaped, reaching 70 mm in height and 70 mm in spread,

branching in one plane. Main stem thick; round or irregular in section.

Hydranths and hydrophores borne irregularly on stem and branches, though

restricted to two opposite sides in certain areas. Small spines sometimes present

in older regions.

Hydrophore double, consisting of a pair of shields, one on each side of

hydranth. Shield broadly triangular with smoothly rounded apex, sometimes

very poorly developed and inconspicuous, usually not supported by ribs from

the trabeculae, seldom more than 0,1 mm in height. Hydranth with up to 29

tentacles.

Gonophores (not reported from South Africa) scattered, arising directly

from coenosarc, oval, shortly stalked, reaching 0,4 x 0,3 mm.

Colour: larger stems dark purple, smaller branches mauve, hydranths

white. Dark brown to creamy white after preservation.

Nematocysts: stenoteles of varying size, 6,3 x 4,5 — 12,6 x 10,8 uw, and

possibly other types too.

Variation. This species is more delicate in appearance than S. procumbens and

the branches more closely set and spreading, giving a reticulate appearance.

The origin of the branches is irregular, though there is a tendency for an alternate

arrangement in the younger parts.

The hydrophores vary in degree of development, and though they are

always double they may be large and triangular or mere elevations of the

trabeculae. They are always smaller than those of S. procumbens.

Distribution outside South Africa. Tropical East Africa and the Seychelles. Type

locality: Wasin, East Africa.

Distribution in South Africa. Santa Carolina, Mocambique, only. 21/35

Solanderia procumbens (Carter, 1873)

Fig. 22

Ceratella procumbens Carter, 1873: 10.

Ceratella spinosa Carter, 1873: 12.

Solanderia procumbens: Millard, 1966a: 444, fig. 4, pl. 1.

60 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 21.

Cladocoryne floccosa. A, hydranth bearing male gonophores; B, macrobasic eurytele,

discharged and undischarged.

Solanderia minima. C, stem; D, part of stem with hydranths; E, hydrophores.

Scale: C in cm, B in mm/100, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 61

Diagnosis. Colony large, fan-shaped, reaching 400 mm in height and 380 mm

in spread, branching in one plane. Main stem of old colonies very thick and

flattened in plane of branching. Smaller branches and main stem of young

colonies round in section. Hydranths and hydrophores borne irregularly on

stem and branches. Spines present in older regions only.

Hydrophore normally scoop-shaped, up to 0,5 mm in height, supported

on lower surface by longitudinal ribs continuous with trabeculae of branch.

Ribs not normally reaching margin. Hydranth with about 15 tentacles.

Gonophores scattered, arising directly from coenosarc, spherical, shortly

stalked, containing four radial canals in male.

Colour: dark brown on stem and larger branches with occasional tinges

of purple, shading to yellowish-brown or ochre on smaller branches (preserved

or dry material).

Nematocysts: large stenoteles 15,3 x 11,7 — 24,3 x 18,0 » and several

other types of unknown category.

Variation. This species is very variable in its general appearance and growth-

form. The branching may be dichotomous, alternate or unilateral, and a strong

development of the last arrangement may give a procumbent appearance to

the colony (possibly due to wave-action or currents). The branches may be

thick and stumpy with rounded tips, or slender with pointed tips, possibly due

to a difference in growth-rate. In older parts of the stem the trabeculae have a

reticulate appearance, but in younger parts the longitudinal ones predominant.

They may be surmounted by prominent chitinous crests. Spines are only found

in older parts of the colony, and may be pointed or spatulate, but tend to be

eroded away.

The hydrophores are particularly variable, and bilobed and double varieties

are common. In old colonies the edges may become eroded between the sup-

porting ribs producing a serrated appearance.

A form occurs with more slender branches and lighter coloration than the

normal one, and with hydrophores predominantly of the double type.

Distribution. Endemic to South Africa. Type locality: Natal.

Distribution in South Africa. West coast of Cape Peninsula to Natal in 12-130 m.

33/18 (s), 34/18 (s), 34/21 (s), 34/22 (s), 33/25, 34/25 (s), 29/31 (d), 29/32 (s)

Doubtful species

Solanderia atrorubens (Gray, 1868)

Dehitella atrorubens Gray, 1868: 579, fig. 1. Brazier, 1887: 576. Spencer, 1892: 19.

Solanderia atrorubens: Marshall, 1892: 12, pl. 5, pl. 7 (figs. 2-4). Vervoort, 1962: 534.

Remarks. This species is said to differ from other species of Solanderia by the more

bushy nature of the colony. The type locality is in doubt, as also is its occurrence in

South African seas. Gray gave the type locality as Australia with a query. Brazier

reported it from Algoa Bay, but gave no description. Spencer, quoting Gray’s descrip-

62 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 22.

Solanderia procumbens. A, stem of normal form (left) and slender form (right); B, I.s. young

gonophore; C, stenotele; D, part of stem with hydranths and gonophores; E, hydrophores

and spines.

Scale: A in cm, C in mm/100, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 63

tion, gave the locality as Delagoa Bay, Africa, which is probably a mistake. Marshall’s

material from Port Natal, which was illustrated, was assigned to S. procumbens by

Millard (1966a).

Solanderia labyrinthica (Hyatt, 1877)

Ceratella labyrinthica Hyatt, 1877: 551, pl. 17 (fig. 30).

Solanderia labyrinthica: Vervoort, 1962: 533. :

Remarks. This species is too inadequately described for there to be any certainty

about its identification. Hyatt mentions one specimen from Mauritius and another

from the Cape of Good Hope.

Solanderia rugosa Marshall, 1892

Solanderia rugosa Marshall, 1892: 13. Vervoort, 1962: 535.

Remarks. This species was founded on material from Port Natal. The description,

which was not illustrated, is too vague for definite recognition.

Family Asyncorynidae

Diagnosis. Colonial hydroids with stolonial or erect habit. Perisarc present on

hydrorhiza and hydrocaulus, not covering hydranth. Hydranth with conical

hypostome, one whorl of capitate oral tentacles, and scattered moniliform aboral

tentacles. Gonophores borne on hydranth amongst the aboral tentacles, form-

ing free medusae. Medusa with marginal tentacles bearing cnidophores.

Introduction. This family was originally created for the stolonial species Asyn-

coryne ryniensis from South Africa, in which the arrangement of tentacles differs

from that in any other form. Picard (1957) assigned to the same genus Zancloidea

philippina Hargitt, 1924, which has a similar arrangement of tentacles on the

hydranth, but an erect and branching stem with better developed perisarc.

These two species have medusoid gonophores in which the marginal

tentacles bear stalked cnidophores similar to those of the Zancleidae, but the

adult medusa is still unknown.

Picard included Asyncoryne and Pteronema Haeckel, 1879 in the family

Pteronematidae, but Pteronema, the type genus, is known only from a some-

what problematical medusa.

One genus only.

Genus Asyncoryne Warren, 1908

Diagnosis. As for family.

Types species: Asyncoryne ryniensis Warren, 1908.

One species only from South Africa.

Asyncoryne ryniensis Warren, 1908

Fig. 20F

Asyncoryne ryniensis Warren, 1908: 285, fig. 3, pl. 46 (figs 13-17). Bouillon, 1974: 144, fig. 10.

Diagnosis. Hydranth reaching 3 mm or more in height, spindle-shaped, with

64 ANNALS OF THE SOUTH AFRICAN MUSEUM

4-6 short, capitate oral tentacles and about 25 scattered moniliform aboral

tentacles. Perisarc present on hydrorhiza and continued over the short hydro-

caulus for 0,6-0,9 mm, not annulated.

Medusa-buds borne in clusters on hydranth body between the moniliform

tentacles. Medusa at release with marginal tentacles bearing cnidophores.

Adult medusa unknown.

Nematocysts of three types (from Bouillon):

(i) Stenoteles. Capsule subspherical, large or small. Present in oral and aboral

tentacles of hydranth and in medusa.

(ii) Macrobasic euryteles. Present in stolon and aboral tentacles of hydranth

and in medusa.

(iii) Microbasic euryteles. Present, but rare, in medusa.

Warren mentions large nematocysts of 27,0 x 19,5 u, which are probably

the large stenoteles, and small ones 10,0 x 8,0 u, which are probably the small

stenoteles.

Distribution outside South Africa. Seychelles.

Distribution in South Africa. Type locality and only record: Park Rynie, Natal,

littoral. 30/30 (1)

Family Cladocorynidae

Diagnosis. Hydranths borne on long, perisarc-covered stems arising from a

creeping hydrorhiza; with a conical hypostome, one whorl of capitate oral

tentacles, and one or more whorls of branched, capitate aboral tentacles.

Gonophores borne on hydranth body amongst the aboral tentacles.

Introduction. The Cladocorynidae are distinguished from all other athecate

families by the nature of the aboral tentacles. For nearly a hundred years

Cladocoryne was the only genus, but in 1963 Mammen added two more:

Lobocoryne and Cladocorynopsis.

The hydranth is comparatively large and conspicuous. There is one whorl

of a few capitate oral tentacles. The aboral tentacles are rather fleshy and bear

several rows of capitula, a condition known as ‘BRANCHED’ or ‘coryniform’

in the literature. The capitula are sessile in Lobocoryne, but stalked in Clado-

coryne and Cladocorynopsis.

The hydrocaulus is generally long, unbranched and covered with perisarc

to immediately below the hydranth.

Reproduction is by fixed sporosacs (C/adocoryne) or medusae (Clado-

corynopsis), but the nature of the adult medusa is unknown.

The Cladocorynidae are closely related to the Asyncorynidae, from which

they may have arisen by the concentration of the nematocyst batteries of the

aboral tentacles on to capitula (Vervoort 1966a).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 65

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

Capitula of aboral tentacles sessile. Aboral tentacles in three whorls [Lobocoryne]

—

— Capitula of aboral tentacles stalked a ; f 2

2. Aboral tentacles in one whorl .. ye 22 a [Cladocorynopsis |

— Aboral tentacles in several whorls fe a Ae oe .. Cladocoryne p. 65

Genus Cladocoryne Rotch, 1871

Diagnosis. Oral tentacles of hydranth stalked. Aboral tentacles in several whorls,

bearing stalked capitula in three longitudinal rows. Tentacles solid, septate.

Gonophores borne amongst the aboral tentacles of hydranth which may be

reduced to a blastostyle, in the form of fixed sporosacs.

Type species :*Cladocoryne floccosa Rotch, 1871.

One species only.

Cladocoryne floccosa Rotch, 1871

Fig. 21A-B

Cladocoryne floccosa Rotch, 1871: 228. Warren, 1908: 284. Behner, 1914: 419, figs 19-23.

Philbert, 1936: 1, figs 1-8. Weill, 1937: 1, figs 1-4. Vervoort, 1941: 190. Millard & Bouillon,

1974: 11, fig. 1D-E. Bouillon, 1974: 145, fig. 11.

Diagnosis. Stem unbranched, or rarely with one lateral branch, reaching a

maximum height of 12 mm; perisarc smooth or irregularly corrugated or

annulated near base, becoming thinner distally to terminate below hydranth.

Hydranth cylindrical, large, 0,5-0,9 mm in height, with a single whorl of

4~7 stalked and capitate oral tentacles, and up to 18 branched aboral tentacles

in 3-4 alternating verticils. Capitula of aboral tentacles up to 17 in number,

stalked, arranged in three longitudinal rows, two rows of 4-7 on latero-aboral

edges and one of 1-3 mid-oral.

Gonophores borne on hydranth among the aboral tentacles on short

pedicels, spherical, reaching 0,34 mm in diameter, forming fixed sporosacs of

the cryptomedusoid type.

Colour: hydranth red with chalky white area around mouth, perisarc horn-

coloured:

Nematocysts of three types:

(i) Macrobasic euryteles. On hydranth body and on gonophores. Capsule bean-

shaped, 28,8 x 11,7 — 31,2 x 15,0 ». Thread: in three sections, the first

unarmed and about 200 » long; the second increasing gradually in width and

armed with spiral bands of fine spines, about 90 » long; the third unarmed and

narrow.

(ii) Large stenoteles. Fairly common in capitula of tentacles. Capsule ovoid,

12,6 x 10,8 — 14,4 x 12,0 pz.

(iii) ?Small stenoteles. Abundant in capitula of tentacles and also present on

hydranth body. Capsule ovoid.6,0 x 5,0 — 6,7 x 5,7 ». Not seen discharged.

Variation. In the South African material the fertile hydranths are normal with

66 ANNALS OF THE SOUTH AFRICAN MUSEUM

well-developed tentacles, but Behner has shown that in European material

gonophore-bearing hydranths may be reduced to blastostyles with the gradual

reduction and loss of the tentacles.

Distribution. Circumglobal in tropical and subtropical waters, occasionally

extending into temperate areas. Type locality: Herm, Channel Islands.

Distribution in South Africa. Natal and Mocambique, in rock-pools. 30/30 (1),

D327) 26/3 210)s 25/382

Family Zancleidae

Diagnosis. Colonial hydroids with a stolonial habit. Hydrorhiza either reticular

or incrusting. Skeleton variously developed; either external and forming a feeble

sheath around base of polyp, or consisting of trabeculae contained within the

incrusting coenosarc and projecting through the surface as spines. Hydranths

either all alike or polymorphic; tentacles scattered, usually capitate (always

in South African genera), rarely filiform. Gonophores borne on hydranth body,

developing into free medusae.

Medusa with, or without, exumbrellar nematocysts confined to specialized

tissue in form of oval or club-shaped patches or elongated tracks; with simple

circular mouth; with four radial canals; with interradial gonads; with two or

four solid marginal tentacles, each with abaxial stalked capsules (cnidophores)

containing nematocysts, or without marginal tentacles; with or without ocelli

(Russell 1953; Bouillon 1974).

Introduction. This family is distinguished mainly by the very characteristic

medusa, whereas the polyp generation has few characters in common. Bouillon

(1974) recognizes four polyp genera: Zanclea Gegenbaur, 1856; Rosalinda

Totton, 1949; Pteroclava Weill, 1931 and his own new genus TJeissiera. Most of

the other medusa genera ascribed to the family by Kramp (1961) have either

been transferred to other families or are of doubtful affinity.

The polyp is typically cylindrical and unbranched, with scattered capitate

tentacles and a conical hypostome, bearing medusa-buds in the lower region.

Pteroclava alone has filiform tentacles. In Rosalinda and Pteroclava all the

hydranths are alike, but in Zanclea costata fertile hydranths may be devoid of

tentacles at certain stages of colony development (Russell & Rees 1936). There

is thus an approach to polymorphism with the differentiation of gonozooids or

blastostyles. In Teissiera polymorphism is firmly established, but has evolved

differently, with the differentiation of separate non-feeding dactylozooids

similar to those of Millepora, and the retention of unmodified polyps for the

dual function of feeding and reproduction.

In Zanclea and Pteroclava the hydrorhiza may be covered with a perisarcal

Sheath, which may extend over the hydrocaulus to the base of the hydranth.

This perisarc may be firm, or soft and membranous, and it may be absent in

young colonies. In Teissiera and Rosalinda the hydrorhiza forms an incrusting

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 67

| j

Fig. 23.

Zanclea sp. A, hydranth of Form 2; B, hydranth of Form 1; C, stenotele.

Staurocladia vallentini. D, hydranth with medusa-bud, redrawn from Gilchrist (1919, as

Cnidonema capensis); E, young medusae, the upper one is about to divide and has three

hypostomes, the lower three have recently divided; F, a single tentacle from medusa;

G, nematocysts of medusa, from left to right an undischarged and a discharged des-

moneme, stenotele.

Scale: C and G in mm/100, the rest in mm/10.

68 ANNALS OF THE SOUTH AFRICAN MUSEUM

basal coenosarc similar to that of Hydractinia, and within this coenosarc is a

trabecular skeleton of a chitin-like material. From it arise spines of various

sizes and shapes. This skeleton, although ‘internal’ and covered by cellular

material (except on the tips of the spines), is ectodermal in origin.

The most obvious character of the medusa is the presence of stalked cap-

sules, or CNIDOPHORES, containing batteries of nematocysts, on the marginal

tentacles. Other features include the restriction of exumbrellar nematocysts to

areas of special tissue, the tendency to lose the ocelli and the splitting of the

gonad into four interradial groups.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Skeleton either absent or consisting of a perisarcal sheath round basal part of polyp.

Hydrorhiza not incrusting ae

— Skeleton consisting of trabeculae contained withinea an 1 incrusting ine ronhiad and

giving off spines... sh a mS <i ae a i oi a4 3

2. Tentacles capitate a we bee A se xa Se Zanclea

— Tentacles filiform .. oe on ; Bs .. [Pteroclava]

3. Colony polymorphic, with ecient and ser ison eae hc [Teissiera]

— Colony not polymorphic, hydranths all alike be oe [Rosalinda]

Genus Zanclea Gegenbaur, 1856

Syn. Gemmaria McCrady, 1858.

Halocharis L. Agassiz, 1862.

Diagnosis. Hydrorhiza reticular, not incrusting. Skeleton external and con-

sisting of a feebly developed perisarcal sheath enveloping the hydrorhiza and

sometimes extending on to the base of the hydrocaulus. Hydranth with scat-

tered capitate tentacles, 3-6 forming a whorl around the mouth.

Medusa with exumbrellar nematocysts; without brood-pouch above

stomach; without oral tentacles; with four simple radial canals; with two or four

marginal tentacles carrying cnidophores.

Type species: Zanclea costata Gegenbaur, 1856.

One or two species from South Africa.

Zanclea sp.

Fig. 23A—-C

Zanclea sp. Millard & Bouillon, 1974: 14, fig. 1F-L.

Diagnosis

Form I. Colony commensal with coral. Hydrorhiza ramifying on coral skele-

ton, giving rise to erect, unbranched hydrocauli which penetrate the soft body

of the coral and emerge through pores at the surface. Hydrorhiza and hydro-

caulus with firm perisarc, which becomes membranous at point of emergence.

Hydranth (plus hydrocaulus) reaching 1,1 mm in height, with 18-28

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 69

stalked capitate tentacles, of which six form an oral whorl and the rest are

irregularly scattered.

Nematocysts of two types:

(i) Stenoteles, 6,0 x 4,8 — 10,8 x 9,0 », abundant on tentacles and hydranth

body. Capsule almost spherical.

(ii) Small bean-shaped capsules, 13,8 x 6,0 », on lower part of hydranth body.

Form 2. Colony commensal with polyzoan. Hydrorhiza ramifying in body of

host, giving rise to erect, unbranched hydrocauli. Hydrorhiza and hydrocaulus

with thin perisarc terminating at point of emergence or slightly above.

Hydranth (plus hydrocaulus) reaching 0,8 mm in height, with 11-24

capitate tentacles, of which 3-5 form an oral whorl and the rest are irregularly

scattered. Tentacles mostly with very short stalks and some completely sessile,

the oral whorl with larger capitula than. the rest.

Medusa-buds borne on hydranth amongst or below the lowest tentacles,

the largest 0,16 mm in diameter and with rudiments of marginal bulbs.

Nematocysts of two types:

(i) Stenoteles, 6,0 x 4,8 — 11,4 x 10,8 », abundant on tentacles and also pre-

sent on hydranth body. Capsule almost spherical.

(ii) ?Macrobasic euryteles, 19,2 x 10,8 — 22,8 x 7,8 u, present on hydranth

body and hydrocaulus. Capsule bean-shaped.

Remarks. These colonies cannot be diagnosed with certainty until the medusae

have been reared, nor is it certain whether one or two species are involved.

Both are closely related to Zanclea costata Gegenbaur, 1856.

Distribution in South Africa. Inhaca only. 26/32 (s)

Family Clavidae

Diagnosis. Solitary or colonial, radially symmetrical polyps with conical hypo-

stome, undifferentiated endoderm and scattered filiform tentacles., Perisarc

present at least on hydrorhiza, absent to well developed on rest of body. Repro-

duction by fixed sporosacs or free medusae.

Adult medusa, when present, with mouth with four lips with continuous

row of nematocyst clusters along margin; with interradial gonads; with four

simple radial canals; with numerous solid margin tentacles not in groups; with

adradial ocelli (Kramp 1961).

Introduction. In the Clavidae the colonies are either stolonial or erect and

branching. Erect stems may be fascicled or unfascicled. Methods of branching

vary. An unusual method occurs in Corydendrium and Turritopsis, where there

is a simple division of the stem into two, the perisarc of the two limbs remaining

adnate for a short distance, then gradually diverging, so that the branches always

arise at a very acute angle.

The hydranth is of simple construction, tubular or spindle-shaped, with

filiform tentacles which are normally irregularly scattered over the body.

Occasionally there is an indication of irregular whorling, but there are never

70 ANNALS OF THE SOUTH AFRICAN MUSEUM

clear and definite whorls with regular arrangement. The hydranth may be

sessile in some stolonial forms, but is usually pedicellate but there is then no

clear demarcation between the hydranth body and the coenosarc of the pedicel

(hydrocaulus).

Perisarc is present at least as a thin membrane clothing the hydrorhiza.

On the rest of the body the development is variable. The body may be completely

naked as in Clava, or the hydrocaulus may be covered with perisarc up to the

base of the hydranth, as in Tubiclava. In Merona the hydranth emerges from a

firm tube of perisarc into which it can be withdrawn on contraction.

Nematophores occur in Merona, where they arise separately from the

hydrorhiza and are enclosed in nematothecae.

In the majority of genera reproduction is by means of fixed sporosacs, in

which indications of medusoid structures, such as radial canals or subumbrella

cavity, may sometimes be seen. The sporosacs may be borne direct on the

hydrorhiza, on the hydrocaulus, or on the hydranth. In Corydendrium the sporo-

sacs are retained within the perisarc of the hydrocaulus and never become visible

externally.

Occasionally the hydranth bearing the sporosacs shows signs of reduction

to a blastostyle and in Merona this differentiation is fully achieved, for the

sporosacs are borne on separate individuals without mouth or tentacles. Such

polymorphism is, however, rare in the family.

Among the South African representatives only Turritopsis produces free

medusae; but there are probably other medusa genera whose hydranth stage

has not yet been discovered.

Most authorities (e.g. Naumov, Thiel) consider that the family Clavidae,

with the scattered hydranth tentacles, is a primitive family and has led to

several more advanced ones by the concentration of the tentacles into one whorl.

This may have occurred along three separate lines:

(i) From stolonial colonies to the Hydractiniidae, with the development of poly-

morphism. Here it might be noted that in Merona (Clavidae) polymorphism

has already been achieved, for there are gastrozooids, gonozooids and dacty-

lozooids. Among the Hydractiniidae, Clavactinia is a primitive member, in

which the hydranth tentacles, although concentrated at the distal end, have

not yet been reduced to one whorl.

(ii) From erect and at least slightly branched stems to the Bougainvilliidae.

Thiel’s family (1962), the Clavopsellidae, represents an intermediate stage,

for the hydranth tentacles are concentrated into definite whorls, which in

Clavopsella and Silhouetta are restricted to the distal end (but not in Balella).

In this work these three genera are included in the Bougainvilliidae because

of the medusa structure of Sil/houetta. Balella’s medusa has four marginal

tentacles, but is otherwise imperfectly known. Clavopsella has sporosacs.

(iii) From erect and slightly branched stems to the Eudendriidae, with the devel-

opment of a trumpet-shaped hypostome and the characteristic gonophores.

In this case Myrionema (Eudendriidae) shows primitive characters in its

elongated hydranth and several whorls of tentacles concentrated at the distal

end.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA ee |

It thus may be difficult to draw a dividing line between the four families

Clavidae, Hydractiniidae, Bougainvilliidae, and Eudendriidae, and in doubtful

cases medusa structure should be the guide.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Colony erect and freely branched 2

— Colony stolonial, polyps at most slightly branched. Gonophores in the form of fixed

sporosacs .. : ; rd ae 4

2. Branches not ndtiaite to stem. ere: in ite form of fixed sporosacs

[Cordylophora]

Branches adnate to stem for some distance .. a i ve 3

. Gonophores forming free medusae es . ss Tiweneoes p. 76

Gonophores in the form of fixed sporosacs contained i in perisarc of stem

Corydendrium p. 72

1 wi |

4. Hydranth, or at least its pedicel (hydrocaulus), surrounded ae pees a 5

— Hydranth naked, perisarc limited to hydrorhiza se 7 6

5. Hydranth retractable into perisarcal tube. See ere on sonia bhistoatylcs.

Nematothecae present ae Merona p. 72

— Hydranth not retractable into perisarc. Gonophores on 1 hydranth body. No nemato-

thecae he ae oe eA rf .. [Tubiclava]

6. Gonophores ee on reeaniis bod be me Suir a Clava p. 71

— Gonophores borne on hydrorhiza aes es Be = .. Rhizogeton p. 75

Genus Clava Gmelin, 1791

Diagnosis. Colony stolonial. Hydrorhiza giving rise directly to sessile hydranths

which are naked except for a low perisarcal collar round base. Hydranth with

scattered filiform tentacles. Gonophores in the form of fixed sporosacs, borne

by the hydranth below the tentacles.

Type species: Hydra multicornis Forskal, 1755.

One species only from South Africa.

Clava sp.

Fig. 24A

Diagnosis. Hydrorhiza reticulate, clothed in thin perisarc which forms a low

collar round the base of the hydranth. Hydranth unbranched, with 21-30

scattered filiform tentacles, reaching a maximum height of 7 mm.

Gonophores unknown.

Nematocysts of two types:

(i) Microbasic euryteles, 0,67 x 0,22 — 0,72 x 0,22 pn.

(ji) Desmonemes, 0,45 x 0,32 pu.

Colour: creamy pink.

Remarks. This species still awaits the discovery of gonophores for final diag-

nosis.

Distribution in South Africa. Cape Peninsula: Melkbosstrand, Bakoven and

Oudekraal, littoral. 33/18 (1)

72 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Corydendrium van Beneden, 1844

Syn. Soleniopsis Ritchie, 1907.

Diagnosis. Colony with erect and branching stem. Stem with firm perisarc,

branches adnate to stem for some distance after origin. Hydranth with scattered

filiform tentacles. Gonophores in the form of fixed sporosacs contained wholly

within perisarc of stem.

Type species: Sertularia parasitica Linnaeus, 1767.

One species only from South Africa.

Corydendrium parasiticum (Linnaeus, 1767)

Fig. 24B-D

Sertularia parasitica Linnaeus, 1767: 1315.

Corydendrium parasiticum: Vervoort, 1946b: 292. Millard, 1959a: 301. Millard & Bouillon,

ee lo wee Ritchie, 1907a: 495, figs 142-143, pl. 26 (fig. 1).

Diagnosis. Stem thick, fascicled and branching, reaching 72 mm; perisarc stiff,

not annulated, terminating abruptly below tentacles of hydranth. Branching

by simple division of the coenosarc and surrounding perisarc into two, the two

tubes running parallel and adnate to one another for a short distance, then

diverging at an acute angle and free from one another to a varying degree.

Branches commonly, but not always, in one plane. Hydranths emerging from

the open ends of the tubes, which are 0,3-0,6 mm in diameter.

Hydranth elongated, 1-2 mm in length when extended, with 22-44 scat-

tered filiform tentacles, the distal four or five arranged in a whorl. Hypostome

prominent and club-shaped. Coenosare swollen within terminal part of

perisarc.

Gonophores (not recorded in South Africa) in the form of fixed sporosacs,

wholly contained within perisarcal tube, arising from coenosarc and lying

parallel to it, in the form of long, slender cylinders without spadix. Female con-

taining about 13 eggs.

Nematocysts of two kinds:

(i) Heteronemes, 7,0 x 4,0 wu.

(ii) Desmonemes, 5,0 x 3,5 pu.

Distribution outside South Africa. Mediterranean, Cape Verde, Seychelles, East

Indies, India, Indo-China, Japan.

Distribution in South Africa. Durban Bay and Inhaca. 29/31 (s, h), 26/32 (s)

Genus Merona Norman, 1865

Diagnosis. Colony stolonial and polymorphic. Gastrozooid unbranched, with

hydrocaulus enclosed in a firm perisarcal tube into ‘which it can be withdrawn.

Hydranth with scattered, filiform tentacles. Gonozooid (blastostyle) borne on

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 73

Fig. 24.

Clava sp. A, hydranths.

Corydendrium parasiticum. B, stem; C, part of stem with hydranths; D, a single hydranth.

Rhizogeton nudum. E, hydranth and male gonophore.

Turritopsis nutricula. F, hydranth; G, stem with hydranths and medusa-buds.

Scale: B in cm, A and C in mm, the rest in mm/10.

74 ANNALS OF THE SOUTH AFRICAN MUSEUM

hydrorhiza, producing fixed sporosacs. Nematophores borne on hydrorhiza,

enclosed in firm perisarcal tube.

Type species: Tubiclava cornucopiae Norman, 1864.

One species only from South Africa.

Merona cornucopiae (Norman, 1864)

Fig. 25

Tubiclava cornucopiae Norman, 1864: 82, pl. 9 (figs 4-5).

Merona cornucopiae: Rees, 1956c: 499, figs 1-3. Cabioch, 1965: 401, figs 1-3. Millard, 1966a:

452, fig. 5 H, J. Millard & Bouillon, 1973: 28, fig. 3 H, J.

Diagnosis. Colony epizootic on the bivalve Crassatella capensis Lamy. Hydro-

rhiza reticulate, with tubes coalesced into mat in denser regions. Gastrozooids

consisting of a perisarc-covered stem and a terminal hydranth. Perisarc forming

a firm tube expanding distally and often curved, reaching 4,3 mm in height.

Hydranth with 16-20 scattered filiform tentacles.

Blastostyle arising separately from hydrorhiza, surrounded by a low flaring

collar of perisarc, without mouth or tentacles, bearing a cluster of gonophores,

reaching a height of 1,4 mm. Gonophores in the form of fixed sporosacs, male

and female on separate colonies.

Fig. 25.

Merona cornucopiae. A, part of colony growing on bivalve showing gastrozooids, one gonozooid

and nematophores; B, nematothecae.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 75

Nematophores usually present, borne on hydrorhiza, 0,3-0,6 mm in height,

completely enclosed in a slender perisarcal tube which expands distally into a

funnel-shaped nematotheca.

Nematocysts of two kinds:

(i) Microbasic euryteles, 16,2 « 4,5 ». Capsule elongated.

(ii) Desmonemes, 7,2 < 2,7 — 3,6 u. Capsule ovoid.

Variation. Outside South Africa M. cornucopiae has been reported on a variety

of different molluscs and on a gorgonian. The presence or absence of nemato-

thecae in South African material is variable and one colony has been found with

none at all. Since nematothecae have now been recorded in the type material

(Cabioch 1965), they can be included in the diagnosis.

Distribution outside South Africa. North Atlantic from the Shetland Islands (type

locality) to the Mediterranean, Pacific and Atlantic coasts of North America,

Seychelles.

Distribution in South Africa. Agulhas Bank, from Still Bay to Algoa Bay, 39-

76 m. 34/21 (s), 34/25 (s)

Genus Rhizogeton L. Agassiz, 1862

Diagnosis. Colony stolonial. Hydrorhiza giving rise directly to naked and sessile

hydranths. Hydranth with scattered filiform tentacles. Gonophores in the form

of fixed sporosacs, borne directly on hydrorhiza.

Type species: Rhizogeton fusiforme L. Agassiz, 1862.

One species only from South Africa.

Rhizogeton nudum Broch, 1909

Fig. 24E

Rhizogeton nudum Broch, 1909: 137, fig. 1. Ritchie, 1910c: 827. Mammen, 1963: 34, fig. 3.

Millard & Bouillon, 1974: 15, fig. 2A.

Diagnosis. Hydrorhiza creeping and reticular, coated with transparent perisarc.

Hydranth reaching 2 mm in height, sessile, naked except for a low perisarcal

collar around base, with 16-26 filiform tentacles irregularly scattered over

distal two-thirds, the proximal tentacles shorter than the distal.

Gonophores in the form of fixed sporosacs, borne directly on hydrorhiza,

completely enveloped in thin perisarc. Male gonophore oval, reaching 0,3 mm

in height. Female unknown.

Distribution outside South Africa. Arctic (type locality: Spitzbergen, 35 m),

Pacific (Christmas Is.), India.

Distribution in South Africa. Mocambique, Inhaca to Santa Carolina. 26/32 (s),

US| 32s OAYBS

76 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Turritopsis McCrady, 1856

Syn. Dendroclava Weismann, 1883.

Diagnosis. Colony with erect and branching stem. Stem with firm perisarc,

branches adnate to stem for some distance after origin. Hydranth naked, not

retractable into perisarc. Gonophores borne on stem, developing into free

medusae.

Medusa with eight or more simple marginal tentacles; stomach with an

apical mass of vacuolated endoderm cells; with ocelli.

Type species: Oceania (Turritopsis) nutricula McCrady, 1856.

One species only from South Africa.

Turritopsis nutricula McCrady, 1856

Fig. 24F-G

Oceania (Turritopsis) nutricula McCrady, 1856: 55; pls 4S.

Turritopsis nutricula: Russell, 1953: 115, figs 54-56, pl. 5 (figs 1-5), pl. 29 (figs 1-3). Vervoort

1968: 5. Millard & Bouillon, 1973: 30, fig. 4C. Millard & Bouillon, 1974: 15.

Turritopsis dorhni: Mammen 1963: 35, fig. 4.

Diagnosis. Stem reaching 5 mm in height, branching irregularly, increasing in

diameter from base to distal end, covered with firm perisarc, branches adnate

and parallel to stem for a short distance, then diverging at an acute angle,

perisarc terminating below hydranth. Hydranth terminal, with 12-38 filiform

tentacles irregularly scattered over distal part, proximal ones shorter than

distal.

Medusa-buds arising below hydranths, pear-shaped, enclosed in perisarc,

with eight marginal tentacles at liberation. Adult medusa (not known from

South Africa) deep bell-shaped; stomach large, cross-shaped, brilliant red;

mouth with four large lips and a row of nematocyst knobs on edge; 80-90

marginal tentacles in a single row.

Nematocysts (medusa): microbasic euryteles and desmonemes.

Variation. Only small unfascicled colonies have so far been found in South

Africa. Mature colonies have thick and fascicled stems and reach about 20 mm

in height. The perisarc of the stem is often in two layers: an inner firm layer,

usually corrugated, and an outer thinner layer, which may have adhering silt.

In newly settled colonies the stem is unbranched and bears a single terminal

hydranth.

Distribution outside South Africa. Circumglobal, mainly in tropical waters but

spreading into temperate waters too. Medusa more widely known and reported

in North Sea, Japan and New Zealand.

Type locality: Charleston Harbour, S. Carolina.

Distribution in South A [frica. Mogambique, Inhaca to Santa Carolina. 26/32 (s),

23/39, 21/39

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA i 5

Family Eudendriidae

Diagnosis. Colonial hydroids with an erect, usually branched stem enclosed in

firm perisarc up to the base of the hydranth body. Hydranth large, radially

symmetrical, with trumpet-shaped hypostome and one or more whorls of

filiform tentacles immediately below it.. Reproduction by fixed sporosacs

borne on the hydranth body below the tentacles; reproductive hydranth often

reduced to a blastostyle. Male gonophore usually with several chambers in

linear series. Young female gonophore with a single egg encircled by a spadix.

Introduction. Members of the Eudendriidae are comparatively easy to recognize,

but identification within the family, particularly in the genus Eudendrium, is

not at all easy, since most of the macroscopic features vary with age and habitat.

The stem may be branched or unbranched, fascicled or unfascicled. It is

always covered with firm perisarc which terminates on or below the base of the

hydranth. The perisarc is usually smooth or wrinkled with characteristic groups

of annulations on the origins of the branches and at other strategic positions.

The hydranth is large and distinguished from all other families of the

Athecata by the wide, trumpet-shaped hypostome which usually gapes open

even in preserved material. Broch (1916) was the first to point out that the

endoderm of the hydranth has become differentiated, the cells of the oral part

of the hypostome being small and ‘indifferent’, and the mucous and digestive

cells being limited to the lower part of the hypostome and the gastral cavity.

The ectoderm is thin over most of the hydranth, but usually there is a shallow

groove round the base of the body where the perisarc of the stem terminates

and where its growth occurs. The ectoderm below this level is thicker, with a

circle of characteristic large cells just below the groove. Mammen (1963)

UNBRANCHED BIFID

capsule

ae p— thin perisarc

cnidophore

thick perisarc BIUAING aleID

HYDRANTH SPADIX OF 9 GONOPHORE

Fig. 26.

Eudendrium, parts of the hydranth and types of female gonophore.

78 ANNALS OF THE SOUTH AFRICAN MUSEUM

maintains that the groove is only visible in the contracted hydranth and that it

therefore cannot be used as a diagnostic character as has been done in the past.

Immediately above the groove there is, in some species, a NETTLE RING, or circle

of large nematocysts. Similar large nematocysts may occur on the hypostome

as well, and they then belong to a different category to the small microbasic

euryteles which are always present on the tentacles. The presence or absence,

and the category, of these large nematocysts provide a useful diagnostic

character.

Reproduction is by fixed sporosacs which develop in a whorl round the

base of the hydranth. Male and female are normally borne on separate colonies,

but there are rare cases of hermaphroditism (E. motzkossowskae). The hydranth

bearing the gonophores is usually atrophied to some extent, but the degree

varies from species to species and sometimes within one species. Thus, the

hydranth may retain its tentacles and continue to function as a normal feeding

individual, or the tentacles may be progressively resorbed as the gonophores

mature to form a blastostyle. Sometimes the tentacles are absent and the

mouth closed from the earliest stage.

Male gonophores typically consist of several bulbous chambers containing

the spermatogenic cells and arranged in linear series. In the earliest stage there

is only one chamber, but as development proceeds additional chambers are

added from below. Thus the number of chambers cannot be used as a diagnostic

character although the maximum number may be characteristic of a species.

The female gonophore consists of a spadix arching round a single large egg.

The spadix may be simple or branched. It provides a reliable diagnostic charac-

ter, although it must be borne in mind that there are several species with an

unbranched spadix and several with a bifid spadix. As the egg matures the spadix

straightens out and arches away from the egg, eventually becoming shed or

resorbed. The egg is left in a perisarcal capsule where it is fertilized and develops

into a planula. As development proceeds the female gonophores lose their

whorled arrangement and, due to lengthening of the blastostyle, become

irregularly distributed along it.

Due to the fact that the earlier systematists based their descriptions on

characters which have since proved to be unreliable, many of the records are

of dubious validity and the distribution of the species uncertain. A new school

of systematists has recently been growing in Europe, including Picard and

Bouillon, in which the nematocysts are being increasingly used for species

diagnosis. These, together with the nature of the female gonophores, and some-

times other specific characters, such as the presence of special nematocyst-

bearing processes, Or CNIDOPHORES, in E. racemosum, make certain diagnosis

possible. The presence of the large nematocysts can easily be determined even

with a low-powered microscope, and with practice their type can often be

recognized in the undischarged state.

In view of these points, the South African material of Eudendrium has been

re-examined and revised. Only that material in which the diagnosis is certain

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 79

has been included in the records. Male colonies and infertile colonies are often

impossible to identify. It should be noted, however, that the genus occurs

abundantly all round the coast and that the various species are probably more

abundant and more widespread than is indicated by the records.

The family Eudendriidae has possibly evolved from clavid stock by the

development of the trumpet-shaped hypostome and the concentration of the

tentacles into one whorl. The genus Myrionema, with its elongated hydranth

and numerous tentacles in several close whorls, may represent a primitive

member.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Tentacles less than 40 in number, arranged in a single whorl .. Eudendrium p. 79

— Tentacles numerous, over 60, arranged in several close whorls on distal end of

hydranth .. nee a ce aa on Be at: [Myrionema]

Genus Eudendrium Ehrenberg, 1834

Diagnosis. Hydranth with short body and one whorl of filiform tentacles.

Type species: Tubularia ramosa Linnaeus, 1758

KEY TO SPECIES

il Epa cibie and mouth of hydranth blocked by a solid plug of endoderm E. angustum

— Hypostome and mouth normal aoe el oe ee aD)

2. Young female gonophore with branching ie Meer Bate with tall, fascicled

stem j et . a eS

— Young female gonophore with curved but unbranched spadix ee ce >)

3. Young female gonophore with spadix giving off several lateral branches on sacl side.

old ones with warty capsule. No large nematocysts Se ". E. deciduum

— Young female gonophore with bifurcating spadix. Large nematocysts present . 4

4. Large nematocysts atrichous isorhizas (and thread coiled many times in figure of 8

when undischarged). Old female gonophore with ores capsule. Male gono-

phore 3- or 4-chambered .. . E. carneum

— Large nematocysts macrobasic eur feles (and butt in on longitudinal coils when

undischarged). Old female oe with smooth Cas Male gonophore 1- or

2- chambered . a ; am 1. &. ritchier

5. No large nSHAEo CSL eaten srrvall aaa afidi enineotic? stem eigassicled n > 6

— Large nematocysts present .. bee ns e. a 48 oo se Papel

6. Stem at least 0,08 mm in diameter Ae me a a ‘ E. capillare

— Stem less than 0,08 mm in diameter ec cat .. . Iantarcticum

7. Large nematocysts macrobasic euryteles (and butt in 3.4 longitudinal coils when

undischarged) ; E. motzkossowskae

— Large nematocysts microbasic euryteles (and butt shorter than capsule, not coiled,

when undischarged). Mature stem tall, fascicled at base, pinnate is _E. ramosum

Eudendrium angustum Warren, 1908

Fig. 27A-B

Eudendrium angustum Warren, 1908: 275, fig. 2, pl. 45 (figs 5-6). Gravier, 1970a: 115.

Diagnosis. Colony arborescent, reaching 76 mm in height. Stem unfascicled,

branching irregularly. Perisarc annulated on origins of branches and at other

80 ANNALS OF THE SOUTH AFRICAN MUSEUM

irregular intervals. Hydranth with 25-30 tentacles, with mouth and hypostome

blocked by a plug of elongated endoderm cells continuous with the digestive

endoderm at base of hydranth.

Gonophores unknown.

Nematocysts of two types:

(i) Large, 23,3 x 10,4 », on hypostome and body of hydranth.

(ii) Small, 5,0 x 2,2 », chiefly on tentacles.

Remarks. This species has not been rediscovered in South Africa, although it

has been reported, but not described, from Madagascar by Gravier (1970a).

Its reproduction and nematocyst types remain unknown.

It might be noted that the blockage of the hypostome by endoderm, the

feature on which the species was founded, may be a transitory phase, for cells

are known to move through the coelenteron in certain species of Hydrozoa

(Braverman 1973).

The large nematocysts in Warren’s diagram could be either macrobasic

euryteles or isorhizas. They are not microbasic euryteles. This would suggest

either E. motzkossowskae or E. carneum.

Distribution outside South Africa. South-east Madagascar.

Distribution in South Africa. Algoa Bay only, 73 m (type locality). 33/25 (s)

Eudendrium ?antarcticum Stechow, 1921

Fig. 27C-D

Eudendrium antarcticum Stechow, 1921b: 225. Stechow, 1925a: 415, fig. 5. Millard, 1957: 183.

non Eudendrium antarcticum Totton, 1930: 140 (=E. tottoni Stechow, 1932).

Diagnosis. Small colonies reaching a maximum height of 3 mm. Stem unfascicled,

unbranched or sparingly branched, smooth for the most part but annulated at

base, on origins of branches and at other irregular intervals, very delicate,

only 9,050,075 mm in diameter. Hydranth with 16-23 tentacles and very large

hypostome.

Male gonophores borne on blastostyles in which the tentacles are completely

atrophied, one-chambered with a terminal tubercle. Female gonophores (not

recorded from South Africa) borne in pairs on tentacular hydranths, with

curved and unbranched spadix, containing one egg (Stechow 1925a).

Only one type of nematocyst: small microbasic euryteles, present on

tentacles, terminal tubercles of male gonophores and elsewhere, 7,2 < 2,7 yp.

Butt with only a few spines on distal end.

Remarks. The position of this material and its identity with the true E. antarcti-

cum remain uncertain. It differs from the other small species of Eudendrium

in the slender stem and the structure of the microbasic euryteles which are

different to any in the northern hemisphere (Picard: personal communication).

Distribution outside South Africa. Bouvet Island, Antarctic (type locality).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 81

Eudendrium angustum. A and B, stems redrawn from Warren (1908).

Eudendrium ?antarcticum. C, hydranths; D, male blastostyles.

Eudendrium capillare. E, colony with female blastostyles; F, very young female blastostyle;

G, older female blastostyles; H, mature female blastostyle with spadices shed; J, male

blastostyles, one mature and one young.

Scale: A in cm, B in mm, the rest in mm/10.

82 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. Two records only: False Bay and Agulhas Bank,

in 18 and 102 m respectively. 34/18 (s), 35/21 (d)

Eudendrium capillare Alder, 1856

Fig. 27E-J

Eudendrium capillare Alder, 1856: 355, pl. 12 (figs 9-12). Picard, 1955: 183. Mammen, 1963:

57, figs 25, 26. Millard & Bouillon, 1974: 17, fig. 3E—-H.

Eudendrium parvum Warren, 1908: 272, fig. 1, pl. 45 (figs 1-4).

Eudendrium ? parvum: Millard, 1959a: 305, fig. 1G—H.

non Eudendrium ?capillare: Millard, 1966a: 454.

Diagnosis. Small colonies common on other hydroids and on weed, reaching a

maximum height of 14 mm. Stem unfascicled, unbranched or sparsely and

irregularly branched, annulated or corrugated on origins of branches and at

other irregular intervals, hydranth pedicels often annulated or corrugated

throughout. Hydranth with 15-23 tentacles.

Male gonophores borne on blastostyles in which the tentacles are completely

atrophied at all stages, one- to three-chambered, sometimes with a terminal

tubercle. Female gonophores borne on hydranths in which the tentacles are

reduced in size, with curved and unbranched spadix, containing one egg. In

older stages the hydranth tentacles completely atrophied, the spadices shed

and the eggs in their transparent capsules distributed irregularly along the

blastostyle pedicel.

Only one type of nematocyst: small microbasic euryteles, abundant on

tentacles and also present in body, 4,8 x 2,1 — 8,0 x 3,0 uw.

Colour: hydranths pale horn-colour (Warren), eggs orange, spadix white.

Distribution outside South Africa. Uncertain, since most of the records in the

literature give insufficient information. Certainly from the North Atlantic and

Mediterranean, and from India. Type locality: Northumberland, U.K.

Distribution in South Africa. Park Rynie in Natal to Santa Carolina in Mogam-

bique, probably more widespread than this. 30/30 (1), 26/32, 25/32, 21/35

Eudendrium carneum Clarke, 1882

Fig. 28

Eudendrium carneum Clarke, 1882: 137, pl. 7 (figs 10-17). Vannucci, 1954: 101, pl. 1 (figs

1-9), pl. 2 (fig. 8), pl. 4 (figs 2-5). Millard, 1959a: 302, fig. 1A—F. Vervoort, 1968: 8.

non Eudendrium 2carneum: Millard, 1966a: 455.

Diagnosis. Colonies tall, much-branched and shrub-like, reaching a height of

162 mm. Stem and larger branches fascicled. Branching irregular. Perisarc

distinctly annulated on origins of branches and at other irregular intervals.

Hydranth pedicels with scattered groups of annulations or completely annu-

lated. Hydranth with 26-33 tentacles.

Male gonophores borne on blastostyles in which the tentacles are com-

pletely atrophied, three- or four-chambered. Female gonophores borne on

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

Fig. 28.

Eudendrium carneum. A, stem; B, part of stem with male blastostyles; C, large isorhiza;

D, microbasic eurytele, undischarged and discharged; E, mature male blastostyle; F and

G, young female blastostyles with bifid spadices; H, old female blastostyle with spadices

shed leaving basket-shaped capsules.

Scale: A in cm, B in mm, C and D in um, the rest in mm/10.

84 ANNALS OF THE SOUTH AFRICAN MUSEUM

hydranths in which the tentacles are reduced in size, with bifurcating spadix,

containing one egg. In older stages the tentacles completely atrophied, the

spadices shed and the developing embryos contained in basket-shaped capsules

distributed irregularly along the pedicel.

Nematocysts of two types:

(i) Large atrichous isorhizas, present on hypostome and hydranth body,

24 x 11 uw. Capsule bean-shaped. Thread coiled in figure of eight in longi-

tudinal axis.

(ii) Small microbasic euryteles, present on tentacles and elsewhere, 9 x 4 nu.

Capsule ovoid. Butt with three large spines on distal end.

Distribution outside South Africa. Atlantic coast of North America, Brazil,

St. Helena, Pacific coast of North America, east tropical Pacific. Type locality:

Fort Wool, Virginia.

Distribution in South Africa. Durban and Inhambane. On ships’ hulls, littoral

and in shallow water. 29/31 (I, s, h), 23/35 (s)

Eudendrium deciduum Millard, 1957

Fig. 29A—F

Eudendrium deciduum Millard, 1957: 184, fig. 2. Millard, 1966a: 456.

Diagnosis. Colonies tall, much branched and tree-like, reaching a height of

161 mm. Stem and larger branches fascicled. Branching irregular, but final

pedicels with a unilateral tendency. Perisarc distinctly annulated on origins of

branches and at other irregular intervals. Hydranth pedicels with groups of

annulations, generally smooth distally. Hydranth with 22-30 tentacles.

Male gonophores borne on hydranths in which the tentacles are completely

atrophied, two- or three-chambered. Female gonophores borne on hydranths

in which the tentacles are reduced in size, with spadix bearing three or four

lateral branches on each side, containing one egg. In older stages the tentacles

completely atrophied, the spadices shed and the developing embryos contained

in warty capsules distributed irregularly along the pedicel.

Colour: larger stems dark brown, smaller ones clear brown to horn-colour,

female gonophores bright orange.

Only one type of nematocyst: small ?microbasic euryteles on tentacles and

body, 6,3 x 2,7 — 8,1 x 3,6 w. Capsule ovoid.

Distribution. Endemic to South Africa. Type locality: False Bay.

Distribution in South Africa. Dassen Island on the west coast to Algoa Bay,

in 4-18 m. 33/18 (s), 34/18 (s), 34/22 (s), 33/25 (s)

Eudendrium motzkossowskae Picard, 1951

Fig. 29G—-H

Eudendrium simplex: Motz-Kossowska, 1905: 56, pl. 3 (figs 18-19).

Eudendrium motzkossowskae Picard, 1951: 339. Millard & Bouillon, 1974: 17, fig. 3J-K.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 85

Diagnosis. Small colonies reaching a maximum height of 12 mm. Stem

unfascicled, unbranched or sparsely branched, smooth for the most part but

annulated on origins of branches and at other irregular intervals, hydranth

pedicels sometimes annulated or corrugated throughout. Hydranth with 16-27

tentacles.

Gonophores borne on hydranths in which the tentacles are not atrophied,

male and female on separate colonies. Male gonophore one- or two-chambered.

Female gonophore (not reported from South Africa) with curved and

unbranched spadix, hermaphroditic, containing one egg within the curvature

of the spadix and one or more masses of spermatogenic cells at summit between

spadix and superficial ectoderm.

Nematocysts of two types:

(i) Large macrobasic euryteles, present on hypostome and lower part of hydranth

body, 15,6 x 6,0 — 31,6 x 14,0 uw. Capsule bean-shaped. Butt 5-6 times

length of capsule, in 3-4 obliquely longitudinal coils when undischarged,

swollen distally to about double the width when discharged, armed with

spirally arranged barbs.

(ii) Small microbasic euryteles, present on tentacles and elsewhere, 6,6 x 2,4 —

7,2 X 3,0 uw. Capsule ovoid.

Variation. Only small colonies have so far been found in South Africa. Neither

Motz-Kossowska nor Picard gives any indication of the size and degree of

branching attainable in the Mediterranean material.

Distribution outside South Africa. Mediterranean only (type locality).

Distribution in South Africa. Mocambique, from Inhaca to Santa Carolina,

littoral to 3 m. 26/32, 24/35 (s), 21/35

Eudendrium ramosum (Linnaeus, 1758)

Fig. 31A—D

Tubularia ramosa Linnaeus, 1758: 804.

Eudendrium ramosum: Allman, 1872: 332, pl. 13. Leloup, 1952: 127, fig. 64. Picard, 1955:

183. Millard, 1966a: 456. Millard & Bouillon, 1973: 32, fig. 4F. Millard & Bouillon, 1974:

19, fig. 3A—D.

Eudendrium ?capillare: Millard 1966a: 454.

Diagnosis. Mature colonies tall, reaching a maximum height of 175 mm; main

stem fascicled at base, sometimes slender and flexuous with roughly alternate

branches, sometimes stiff and bushy with irregular branches; branches unfas-

cicled. Small colonies commonly occurring on weed and other hydroids, reach-

ing 10-20 mm, with unfascicled stems which may be unbranched or sparingly

branched in a roughly alternate fashion. Perisarc smooth for the most part but

with groups of a few distinct annulations above origins of branches and at other

irregular intervals. Hydranth pedicels annulated in basal region. Hydranth

with 14-29 tentacles.

Gonophores borne on hydranths in which the tentacles are atrophied to a

varying degree. Male gonophores one- or two-chambered. Female gonophores

86 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 29.

Eudendrium deciduum. A, stem; B—D, young female gonophores showing branching spadix;

E, part of sterile stem; F, branch with two male blastostyles.

Eudendrium motzkossowskae. G, mature male blastostyle; H, large macrobasic eurytele,

discharged and undischarged.

Scale: A in cm, E and F in mm, H in mm/100, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 87

with curved and unbranched spadix which is shed later leaving a smooth

transparent capsule, containing one egg.

Nematocysts of two types:

(i) Large microbasic euryteles, present on hypostome and lower part of hydranth

body, on spadix of female gonophore and on distal end of male gonophore,

rather variable in size, 18,0 7,2°— 28,8 x 13,8 ». Capsule bean-shaped.

Butt about ? length of capsule, increasing in diameter distally but not coiled

when undischarged, when discharged held at right angles to capsule and

dilated distally to about double its width. Spines spirally arranged on butt

and decreasing in length distally.

(ii) Small microbasic euryteles, present on tentacles and elsewhere, 5,8 « 2,7 —

8,4 x 4,2 uw. Capsule ovoid.

Colour: hydranth body yellowish to orange-pink, tentacles and hypostome

white.

Variation. This species has a variable growth-form and can be distinguished

with certainty only on the nematocysts. It is the ‘only South African species

with large microbasic euryteles.

The degree of atrophy of the blastostyle is variable. The female gonophores

are borne on fully developed hydranths, and the tentacles are then gradually

resorbed until by the time the spadix is shed there is no sign of them left. In the

male, gonophores may be borne on hydranths with their tentacles in any stage

from fully-formed to completely atrophied. The gonophores are one-chambered

when young, becoming two- or three-chambered when ripe.

In some colonies the stem is almost completely annulated throughout.

Distribution outside South Africa. North Atlantic, from the Arctic to Cape

Verde, Mediterranean, Seychelles. Further distribution doubtful. Type locality:

Kentish shore, U.K.

Distribution in South Africa. From off Saldanha Bay to Inhaca, littoral to 84 m.

Probably more abundant than records indicate. 33/17 (s), 33/18 (s), 34/18 (I, s),

34/25 (s), 33/27 (1), 31/29 (1), 26/32 (s), 25/32

Eudendrium ritchiei sp. nov.

Fig. 30

Eudendrium annulatum(?): Ritchie, 1909: 70. Millard, 1966a: 454.

Eudendrium ?carneum: Millard, 1966a: 455.

Holotype. Abundant male and female colonies. Saunders Rocks, Sea Point,

littoral. Cat. no. SAM-H1803.

Description of holotype. Colony stiff and spiky, reaching a maximum height of

28 mm. Stem fascicled, branching irregularly and in all planes; branches stiff

and making an angle of about 45° with stem, often rebranching. Perisarc strongly

annulated almost throughout, but with occasional smooth areas on some of the

youngest pedicels. Hydranth with 16-21 tentacles. No cnidophores.

88 ANNALS OF THE, SOUTH AFRICAN MUSEUM

Male and female blastostyles on separate stems. Male with no sign of ten-

tacles at any stage; bearing a circle of gonophores which are one- or two-

chambered. Female with a cluster of reduced tentacles which are completely

resorbed later; bearing a circle of 4-6 gonophores which become irregularly

distributed as they mature. Young female gonophore with a bifurcating spadix

surrounding the single egg, but sometimes the two limbs unequally developed

or one of them rudimentary. Old female gonophore oval, with a smooth trans-

parent capsule surrounding the developing embryo.

Nematocysts of two types:

(i) Large macrobasic euryteles, present on hypostome and body of hydranth, on

spadix of female gonophore and on terminal tubercle of male gonophore,

23,4 x 8,4 — 27,6 x 10,8 ». Capsule bean-shaped. Butt coiled longitudinally

in one and a half coils when undischarged, reaching a length of 74 » when

discharged and increasing in diameter smoothly from about 1,2 » proximally

to 2,7 pu distally, armed with spiral bands of spines.

(ii) Small microbasic euryteles, abundant on tentacles of hydranth and else-

where on the body, 6,0 x 3,6 — 9,6 x 3,6 uw. Capsule bean-shaped. Butt

about 6,3 » in length when discharged, bearing spines distally.

Colour: stem pale horn-colour to dark brown; hydranths and female

gonophores orange, male gonophores white.

Variation. From colonies other than the holotype, stems may reach 50 mm and

hydranths may have 15-24 tentacles.

The annulation of the perisarc varies. It may be completely annulated

throughout, or there may be smooth areas on the pedicels and the stem itself.

The annulation is always more strongly developed than in any other South

African species.

Remarks. This species is very close to E. carneum and E. racemosum, both of

which have a bifurcating spadix in the female gonophore. It differs from both

of these in the cnidome and in the annulated stem. It is to this species that

Ritchie’s material from South Africa, described as FE. annulatum, must be

ascribed.

Distribution. Endemic to South Africa.

Distribution in South Africa. Saldanha Bay to Oudekraal, littoral to 46 m.

33/17 (s), 33/18 (is)

Family Bougainvilliidae

Diagnosis. Colonial (rarely stolonial) hydroids with an erect, often branched,

stem enclosed in firm perisarc which may terminate below the hydranth body

or continue over it as a pseudohydrotheca. Hydranth radially symmetrical,

with conical hypostome and one or more definite whorls of filiform tentacles.

Reproduction by fixed sporosacs or medusae.

Adult medusa, when present, with simple tubular mouth, with four or

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 89

24 WG,

A A

sn ag Sao

Ss Aye

CB WH §

A ©

A SS

oxo Wee es

ays

Qn» BY

Lae?”

OD I

als RP

=) 2] MA

BY RS

HS BS) hp

LUT ITt

LLY

Fig. 30.

Eudendrium ritchiei, sp. nov., all from holotype. A, stems; B, part of stem with hydranuis and

male blastostyle; C, male blastostyle; D, young female blastostyle; E, old female

blastostyle with spadices shed; F, nematocysts, from left to right three macrobasic

euryteles (two discharged, one undischarged), and two microbasic euryteles (one undis-

charged, one discharged).

Scale: A in cm, F in mm/100, the rest in mm/10.

90 ANNALS OF THE SOUTH AFRICAN MUSEUM

eight usually branched oral tentacles inserted above mouth opening, four

radial canals, solid marginal tentacles often in groups on marginal bulbs, with

or without ocelli, with interradial gonads.

Introduction. The Bougainvilliidae is a fairly well-defined family and the

medusae in particular are very distinctive.

The stem, which may be branched or unbranched, fascicled or unfascicled,

is always coated in firm perisarc, and this perisarc may terminate below the

hydranths as in Clavopsella and Silhouetta or it may extend over the body of

the hydranth as a PSEUDOHYDROTHECA. This structure, unlike the true hydro-

theca of the Thecata, has little form; it adheres closely to the ectoderm of the

hydranth and is often gelatinous with adhering silt granules. The hydranth on

contraction may partially or completely withdraw into it, when it becomes

broader and shorter and often wrinkled. In Bougainvillia (some species) and

in Rhizorhagium* the pseudohydrotheca invests only the lower part of the

hydranth body, but in Bimeria it covers the bases of the tentacles as well, so

that each tentacle has a sheath around its base. In Bimeria rigida the pseudo-

hydrotheca covers the whole body as far as the mouth, and the tentacles almost

to their tips. Since the perisarc below the tentacles is particularly firm the

hydranth in this species has little motility and the tentacles are held out in a

rigid flower-like crown.

The hydranth is of fairly simple construction, though there is a differentia-

tion of the endoderm into an oral region rich in gland cells and a gastral region

below the tentacles. Unlike the Eudendriidae the hypostome is conical. Most

species have a single whorl of filiform tentacles, but there is more than one

whorl in Clavopsella, Silhouetta and Balella. As mentioned on p. 70 these

genera are considered to be primitive in that the tentacles have not yet settled

down into a single whorl, and are included in the Bougainvilliidae on the strength

of the medusa structure of Si/houetta. In Bimeria rigida the tentacles were

described as capitate by Warren (1919a), but there is only an indistinct swelling

of the tips where they escape from the constricting perisarcal sheath.

The gonophores are usually borne on the stem or hydranth pedicels, more

rarely on the hydrorhiza. In Dicoryne they are borne on reduced hydranths,

or blastostyles, which are without mouth or tentacles, but have a prominent

hypostome armed with nematocysts.

The gonophores may be in the form of fixed sporosacs (Bimeria, Rhizor-

hagium, Clavopsella, Garveia) or may be released as free medusae. In Dicoryne

the sporosacs are unusual. Although essentially styloid in structure they are

released and free-swimming with the aid of a coating of cilia and two long

tentacles. The tentacles are not comparable with the marginal tentacles of a

medusa, for they arise from the proximal (attached) end of the sporosac.

Free-swimming medusae are released in Bougainvillia, Balella, Silhouetta

and Thamnostoma. Bougainvilliid medusae are easily recognized, even in their

* For Rhizorhagium the conception and definition of Rees (1938) are adopted.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 9]

young stages, by the oral tentacles which do not arise from the rim of the

mouth but just above, leaving the mouth free. However, at any rate in the genus

Bougainvillia, identification to the species level is difficult for it depends largely

on the structure of the adult medusa, the hydranth generation being very

variable in growth-form and having few reliable diagnostic characters.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Hydranth with more than one whorl of tentacles 2

— Hydranth with one whorl of tentacles he 4

2. Hydranth with two whorls of tentacles, one at reeiinal end aad one Sond

widest part. Gonophores producing free medusae cA, [Balella]

— Hydranth with 2-4 whorls of tentacles closely approximated around mouth . 3

3. Gonophores producing free medusae Be bs ae ~~ [Sithouetra]

— Gonophores in the form of fixed sporosacs 3 ay ee Clavopsella p. 100

4. Perisarc not continued over tentacles me ae a bs of 5

— Perisarc continued at least part-way over tentacles st : a me 8

5. Producing medusae. Medusa with groups of marginal fentacles Bougainvillia p. 95

— Not producing medusae ae - ¥: S08 ni ss i at 6

6. Producing swimming sporosacs .. ae Re 5 x; ne me p. 101

— Producing fixed sporosacs

7. Stem with one terminal hydrant eat aie. one or two itera ones

Rhizorhagium p. 103

— Stem much-branched or : £3 .. [Garveia]

8. Producing medusae. Medusa with eatery carnal entacles .. [Thamnostoma]

— Producing fixed sporosacs .. ne, Pe - i e .. Bimeria p. 91

Genus Bimeria Wright, 1859

Diagnosis. Colony stolonial or with erect, branching stem. Stem with firm

perisarc which also extends over part or all of the hydranth as a pseudohydro-

theca and sheaths the proximal parts of the tentacles. Hydranth with one whorl

of tentacles. Gonophores in the form of fixed sporosacs, completely invested in

perisarc.

Type species: Bimeria vestita Wright, 1859.

KEY TO SPECIES

1. Estuarine. Stem branching profusely and at least several cm in height B. fluminalis

— Marine. Stem unbranched or slightly branched, under 2 cm in height ae BS ieee?

2. Gonophores normally borne on stem, stem normally branched : .. B. vestita

— Gonophores borne only on hydrorhiza, stem never branched .. a .. 8B. rigida

Bimeria fluminalis Annandale, 1915

Fig. 31E-K

Bimeria fluminalis Annandale, 1915: 111, fig. 10, pl. 9 (figs 3-3a). Millard, 1959a: 309, fig. 4.

Vervoort, 1964: 138.

Diagnosis. Hydrorhiza forming a matted feltwork. Stem unfascicled, flexuous

to stiff, profusely branched in a roughly alternate fashion, reaching a maximum

ANNALS OF THE SOUTH AFRICAN MUSEUM

AURA

Fig. 31.

Eudendrium ramosum. A and B, male blastostyles; C, young female blastostyles; D, nemato-

cysts, from left to right large microbasic eurytele discharged and undischarged, a small

microbasic eurytele.

Bimeria fluminalis. E, part of colony; F, t.s. female gonophore with egg; G, t.s. female

gonophore with planula; H, t.s. male gonophore; J, hydranth and two young female

gonophores, one with an egg; K, microbasic eurytele.

Abbreviations: e: egg; ect: ectoderm; m: male Spermatogenic cells; p: perisarc; sp: spadix.

Scale: E in cm, D and K in mm/200, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 93

height of 330 mm. Perisarc annulated on base of stem, origin of branches and

hydranth pedicels, continued over base of hydranth body as a thick pseudo-

hydrotheca, of which a very thin extension covers the bases of the tentacles,

covered with adherent silt. Hydranth with 10-12 tentacles, partially retractable

into pseudohydrotheca. :

Gonophores borne singly or in clusters on hydranth pedicels, pedicellate,

completely clothed in perisarc, with no radial canals or tentacle rudiments,

male and female on separate stems. Male ovoid, reaching 0,5 mm in length.

Female ovoid, containing a single egg on one side of the curved spadix, reaching

0,4 mm in length. Egg developing into a planula in situ.

Nematocysts of two types:

(i) Desmonemes, 3,5 x 2,5 wu.

(ii) Microbasic euryteles, 7,0 x 4,5 » (maximum).

Variation. The stem is sometimes straight and sometimes geniculate in the distal

region. The development of the perisarc covering the tentacle bases is variable;

in the type material there is usually a distinct layer, but in the South African

material this part is very poorly developed and usually only discernible in

sections.

Distribution outside South Africa. Tropical Indo-Pacific including India, the

Gulf of Siam and W. Borneo. Type locality: Chilka Lake, Calcutta.

Distribution in South Africa. Richard’s Bay and St. Lucia estuaries, on

mangroves, logs, etc. 28/32 (I)

Bimeria rigida Warren, 1919

Fig. 32A-—B

Bimeria rigida Warren, 1919a: 1, figs 1-2, pls 1-2.

Diagnosis. Colony growing on weed. Hydrorhiza with clasping processes and

with internal thickenings of perisarc in some areas. Stem unfascicled,

unbranched, narrower at base than at distal end, bearing a single terminal

hydranth, reaching a maximum height of 3 mm. Perisarc indistinctly annulated,

especially at base and distal end, continued over body of hydranth as a well-

developed pseudohydrotheca. Pseudohydrotheca in proximal region stiff,

longitudinally ridged and continued along the tentacles almost to the tips;

in distal region thick and soft, completely enveloping the conical hypostome,

with adherent silt. Hydranth about 0,6 mm in height to tip of hypostome, with

16-33 stiff tentacles held alternately elevated and depressed and swollen at the

tips where they emerge from the perisarc, with an ectoderm-lined chamber

distal to the mouth, with four endodermal ridges in hypostome.

Gonophores borne on hydrorhiza, pedicellate, completely enclosed in

perisarc. Male oval to spherical, reaching 0,5 mm in length, with no radial

canals or tentacle rudiments, with branching spadix. Female unknown.

94 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 32.

Bimeria rigida, A, hydranth; B, l.s. male gonophore redrawn from Warren (1919a).

Bimeria vestita. C, fertile stems; D, contracted hydranth showing perisarcal sheaths round

tentacles; E, F and G, stages in development of female gonophore, the last two drawn

without the perisarcal coat; H, male gonophore.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 95

Nematocysts: microbasic euryteles, 7,2 x 3,0 — 9,0 x 4,2 yu.

Colour: pale horn-colour.

Distribution. Endemic to South Africa. Type locality: Port St. Johns.

Distribution in South Africa. Transkei coast, in rock pools. 31/29 (1), 31/30 (1,

Bimeria vestita Wright, 1859

Fig. 32C-H

Bimeria vestita Wright, 1859: 109, pl. 8 (fig. 4). Allman, 1872: 297, pl. 12 (figs 1-3). Millard,

1966a: 449, fig. SA-F.

Leuckartiara vestita f. nana: Vervoort, 194665: 294.

Diagnosis. Colony usually epizootic on other hydroids. Stem unfascicled,

delicate, either unbranched and with one terminal hydranth, or branching,

and rarely rebranching, in a roughly alternate manner, reaching a maximum

height of 18 mm but usually much less. Perisarc annulated on base of stem,

origin of branches and at other irregular intervals, continued over hydranth

body and base of hypostome and forming distinct sheaths over the basal parts of

the tentacles, often covered with adherent silt. Hydranth with 10—20 tentacles.

Gonophores borne on stem and branches, rarely on hydrorhiza, pedi-

cellate, invested in thick gelatinous perisarc, with no radial canals or tentacle

rudiments, male and female on separate colonies. Male elongate-oval with

branching spadix, reaching 0,3 mm in length (without perisarc). Female oval to

spherical, containing one terminal ovum, reaching 0,2 mm in length (without

perisarc). Egg developing into a planula in situ.

Variation. The South African material is not so richly branched as some of

that described from other areas.

Distribution. Cosmopolitan. Type locality: Firth of Forth, U.K.

Distribution in South Africa. All round the coast from the Orange River on the

west to Inhaca on the east, 5-88 m. 28/16 (s), 34/18 (s), 34/20 (s), 34/21 (s),

34)221(S), 33/25, 33/26 (S)333/27 (S); 26) 32s)

Genus Bougainvillia Lesson, 1836

Diagnosis. Colony erect with branching stem, or (rarely) stolonial. Stem with

firm or soft perisarc which often extends over the base of the hydranth as a

pseudohydrotheca but never covers tentacle bases. Hydranth with one whorl of

filiform tentacles. Gonophores developing into free medusae.

Medusa with four unbranched radial canals and a circular canal, four

dichotomously branched, capitate oral tentacles inserted above mouth opening,

marginal tentacles all alike, arising in groups from four marginal bulbs, with

ocelli.

Type species: Bougainvillia macloviana Lesson, 1836.

96 ‘ANNALS OF THE SOUTH AFRICAN MUSEUM

KEY TO SPECIES

1. Perisarc strongly wrinkled throughout. Colony epizootic on parasitic isopods

B. meinertiae

— Perisarc smooth for the most part, but wrinkled or annulated in certain me Not

epizootic on parasitic isopods = : 2

2. Stem low-lying, delicate, never fascicled, aubraictied or wnat tances Mea

medusa with well-developed peduncle, oral tentacles branching about 8 times, marginal

bulbs with about 53 tentacles ae : Be B. macloviana

— Stem erect, stiff, fascicled in larger Polonies branching pretncely, Mature medusa with

very slight peduncle, oral tentacles branching 1-6 times, marginal bulbs with 3-9

tentacles ae aS Se Re ts ae ss a Ae .. B. ramosa

Bougainvillia macloviana (Lesson, 1830)

Fig. 33A—C

Cyanaea bougainvillii Lesson 1830: 118, pl. 14 (fig. 3).

Bougainvillia macloviana: Russell, 1953: 173, figs 86-88. Millard, 1959b: 242, fig. 1A—C.

Vannucci & Rees, 1961: 69. Edwards, 1966: 147, 149. Millard & Bouillon, 1973: 22,

eae maclovianus: Vanhoffen, 1910: 284, fig. 10.

Diagnosis. Hydrorhiza forming a branching network. Stem slender, unfascicled

and low-lying, unbranched or branching irregularly, narrower at base than at

summit, reaching a maximum height of 8 mm. Perisarc smooth or wrinkled,

more deeply corrugated on base of stem and origins of branches, continued over

base of contracted hydranth as a gelatinous pseudohydrotheca. Hydranth with

8-12 tentacles.

Medusa-buds arising singly from hydrorhiza, stem or branches, larger than

hydranths, shortly stalked, spherical, enclosed in perisarc, reaching a diameter of

0,4 mm (without perisarc), before liberation with four unbranched, capitate

oral tentacles and four marginal bulbs, each of the latter with two ocelli and

two marginal tentacles.

Adult medusa globular, with moderately thick jelly. Outer surface of bell

with interradial furrows. Stomach short with large peduncle and four perradial

lobes along peduncle. Oral tentacles four, branching dichotomously about eight

times. Marginal bulbs V-shaped, each bearing about 53 tentacles in a double

row and as many ocelli. Gonads interradial, hanging in folded bands along the

stomach lobes. Reaching 9,0 mm in depth and 8,2 mm in diameter. Colour:

marginal bulbs, gonads and stomach reddish-brown, ocelli black, the rest

transparent.

Nematocysts of two kinds, present in hydranths and medusae:

(i) Desmonemes. Capsule ovoid, thread in 1% coils. Smaller in hydranth

(3,5 x 2,0 — 4,0 x 3,0 ») than in medusa (6,3 x 3,6 — 8,1 x 4,1 p).

(ii) Microbasic euryteles. Capsule bean-shaped, butt about 2 length of capsule.

D4 X27 — 7,2 X36 ee

Variation. The measurements and tentacle numbers given above are from South

African material only. In material from elsewhere, however, the hydranth may

have as many as 16 tentacles and the medusa-buds may reach a diameter of

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 97

0,75 mm and have up to five marginal tentacles on each bulb at liberation.

Similarly the adult medusa may reach a depth of 15 mm and may have up to 65

tentacles on each marginal bulb.

Distribution outside South Africa. Hydranth: Kerguelen, Seychelles. Medusa:

Subantarctic, North Sea, Firth of Clyde. Type locality: Falkland Islands.

Distribution in South Africa. Hydranth: Saldanha Bay, Table Bay and off Still

Bay, 15-73 m and on ships’ hulls. Medusa: Saldanha Bay, Langebaan Lagoon.

33/18 (s, h), 34/21 (s)

Bougainvillia meinertiae Jaderholm, 1923

Fig. 33D

Bougainvillia meinertiae Jaderholm, 1923a: 3, fig. 1. Vannucci & Rees, 1961: 72.

Diagnosis. Colony epizootic on the parasitic isopod Codonophilus (Meinertia)

imbricata (Fabr.) which lives in the buccal cavity of fish. Stem erect, fascicled

at base, branching freely, reaching a maximum height of 10 mm. Perisarc thick,

especially near base, very strongly and irregularly wrinkled throughout, con-

tinued over base of hydranth body as a thin and smooth pseudohydrotheca into

which the hydranth can be partially retracted. Hydranth with about 14 tentacles.

Medusa-buds arising from hydranth pedicels, smaller than hydranths,

sessile or shortly stalked, pear-shaped to spherical, about 0,16 mm in diameter.

Marginal tentacles probably eight.

Remarks. This material differs only from that assigned to B. ?ramosa in the more

extensive wrinkling of the perisarc. In view of its unusual habitat it is retained as

a separate species until more material is forthcoming.

Distribution. Endemic to South Africa.

Distribution in South Africa. Agulhas Bank east of Cape Agulhas in 73 m (type

locality). 34/20 (s), 34/21

Bougainvillia ?ramosa (van Beneden, 1844)

Fig. 33E-H

Eudendrium ramosum van Beneden, 1844: 57, pl. 4 (figs 10-13).

Bougainvillia ramosa: Allman, 1872: 311, pl. 9 (figs 5-7). Stechow, 1925a: 411. Russell, 1953:

153, fig. 74, pl. 8 (fig. 1), pl. 9 (figs 4-5). Millard, 1959b: 244. Vannucci & Rees, 1961: 82.

Edwards, 1966: 145.

Bougainvillia fruticosa: Allman, 1872: 314, pl. 9 (figs 1-4).

Bougainvillia muscus: Allman, 1872: 317, pl. 10 (figs 1-3).

Bougainvillia van Benedeni: Jaderholm, 1909: 46, pl. 3 (fig. 5).

Bougainvillia sp.: Millard, 1966a: 451. Millard, 1968: 255.

Diagnosis. Stem erect, unfascicled or weakly fascicled, branching profusely

and irregularly, narrower at base than at summit, reaching a maximum height

of 53 mm. Branches forming an acute angle with the stem. Perisarc smooth for

98 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 33.

Bougainvillia macloviana. A, nematocysts from medusa: desmoneme and microbasic eurytele;

B, fertile stem; C, adult medusa.

Bougainvillia meinertiae. D, part of fertil

Bougainvillia 2?ramosa. E, fertile colony;

H, newly liberated medusae.

Scale: C and E in mm, A in mm/100, the rest in: mm/10

e stem, redrawn from Jaderholm (1923a).

F, hydranth showing stolonization; G, medusa-buds;

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 99

the most part, wrinkled, corrugated or distinctly annulated on origins of

branches and on part or all of final pedicels, continued over base of hydranth

body as a pseudohydrotheca. Stolonization common on all parts of colony.

Hydranth with 9-15 tentacles.

Medusa-buds arising in groups from hydranth pedicels and smaller

branches, smaller than hydranths, shortly stalked, pear-shaped when young.

Medusa at liberation subglobular, about 0,4 mm in diameter, with four

capitate, unbranched oral tentacles and four marginal bulbs, each of the latter

with two marginal tentacles and two ocelli.

Adult medusa of B. ramosa (not recorded from South Africa) semiglobular,

with thick jelly. Stomach short, sometimes with very slight peduncle. Oral

tentacles four, branching dichotomously once or twice (rarely up to six times).

Marginal bulbs small and oval, each bearing 3-9 tentacles (usually 4-5) and as

many ocelli. Gonads interradial, extending adradially along radial canals to a

slight extent. Reaching 3-4 mm in depth and diameter.

Nematocysts of two kinds:

(i) Desmonemes, 3,6 x 2,5 — 4,2 X 3,2 pz.

(ii) Microbasic euryteles, 5,9 x 2,7 — 8,1 x 3,6 uw. Capsule elongate bean-shaped.

Colour: hydranth creamy white with pink endoderm.

Variation and remarks. B. ramosa is very variable in its growth-form and the

several European forms have been described under different specific names. In

f. musca the stem is short, reaching about 15 mm, unfascicled and little branched.

In f. fruticosa the stem is tall, reaching about 50 mm, fascicled and much-

branched; the pseudohydrotheca covers about one-third of the hydranth and is

membranous and corrugated when contracted. F. ramosa is similar but the

pseudohydrotheca forms a thin but distinct cup into which the hydranth can

be completely withdrawn. F. vanbenedenii is characterized by the abundant

stolonization; the stem is fascicled or unfascicled and irregularly branched.

The South African material covers most of these variations.

Although young medusae have been released in the laboratory, they have

not been reared to a stage where it is possible to be certain of the identification.

For this reason, and since no adult medusae of B. ramosa have as yet been

recorded from the South African coast, the identification is provisional. There

is a possibility of confusion with B. fulva which has been recorded from the

East coast of Africa (Kramp 1965; Bouillon personal communication) and

whose hydroid stage is as yet unknown.

Distribution outside South Africa. ‘Probably in all temperate and subtropical

regions’ (Vannucci & Rees 1961). Type locality: Ostend.

Distribution in South Africa. Langebaan Lagoon to Port Elizabeth, littoral to

126 m and on ships’ hulls. 33/18 (1, h), 34/18 (s, h), 35/19 (s), 34/20 (s), 35/20

(d), 34/21 (s), 34/22 (s), 34/23 (1, s, d), 33/25

100 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Clavopsella Stechow, 1919

Diagnosis. Stem erect, branched or unbranched, with firm perisarc terminating

at base of hydranth. Hydranth with tentacles in two to four closely alternating

verticils immediately below hypostome. Gonophores in the form of fixed sporo-

sacs or degenerate medusae without marginal tentacles, radial canals, mouth or

oral tentacles.

Type species: Pachycordyle weismanni Hargitt, 1904.

One species only from South Africa.

Clavopsella navis (Millard, 1959)

Fig. 34A—D

Rhizorhagium navis Millard, 19596: 244, fig. 2.

Clavopsella quadranularia Thiel, 1962: 227, figs 1-28. Thiel, 1970: 482.

Diagnosis. Hydrorhiza creeping. Stem unbranched (in South African material),

bearing a single terminal hydranth, reaching a maximum height of 5 mm. Peri-

sarc often wrinkled, especially near base, terminating below hydranth.

Hydranth with 8-16 tentacles arranged in 2-4 closely alternating verticils

immediately below hypostome, 0,4-1,3 mm in length from perisarc.

Gonophores in the form of fixed sporosacs, borne in an irregular spiral on

stem below hydranth, pedicellate, completely clothed in perisarc, without

tentacle rudiments or radial canals. Female containing about eight eggs usually

in one tier, which develop into planulae in situ.

Nematocysts of two types:

(i) Desmonemes, 3,5 x 2,0 pu

(ii) Microbasic euryteles, 6,5 x 3,0 ». Capsuie bean-shaped, butt about two-

thirds length of capsule.

Colour: creamy white, with pink tinges in hypostome of hydranth and

spadix of gonophore. .

Variation and remarks. Re-examination of the type material of this species

established the fact that in the larger hydranths the tentacles are arranged in

as many as four alternating verticils, whereas in the smaller ones (which may be

sexually mature) there are only two. It thus becomes necessary to transfer the

species from Rhizorhagium to Clavopsella. y

In 1962 Thiel published his excellent account of Clavopsella quadranularia

from the Kiel Canal. This species differs from C. navis in only a few points,

mainly in the fact that in the centre region of well-established colonies the stem

branches to produce lateral hydranths of the first and second order. In its

maximum development, thus, the colony is a raceme and reaches a height of.

30 mm. Other minor differences are the larger number of hydranth tentacles

(14-24) and slightly larger desmoneme nematocysts (4-6 x 3-4 y). Thiel also

discussed the systematic position of Clavopsella and the closely related Balella

and established a new family, the Clavopsellidae, for their inclusion.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 101

In 1972 Dr Thiel and the author had the opportunity of comparing material

and we agreed that the species were synonymous, the South African material

heing a younger colony in its first phase of reproduction.

Later, Millard & Bouillon (1973) established the genus Sil/houetta for a

species with several whorls of tentacles and bougainvilliid medusae, and

expressed the opinion that all genera with more than one whorl of tentacles

should be included in the Bougainvilliidae.

It is possible that C. navis has been transported from one to the other of its

widely separated localities on ships’ hulls. The variations described by Thiel

can be expected to occur in South Africa when a well-established colony is

discovered.

Distribution outside South Africa. Kiel Canal.

Distribution in South Africa. One record only, from a ship’s hull in Table Bay

(type locality). 33/18 (h)

Genus Dicoryne Allman, 1859

Diagnosis. Stem erect, branched or unbranched, with conspicuous perisarc

terminating on or below hydranth body but never continued over tentacle

bases. Hydranth with one whorl of filiform tentacles. Gonophores borne on

reduced hydranths (blastostyles) and released as free-swimming, ciliated

sporosacs.

Type species: Eudendrium confertum Alder, 1856.

One species only from South Africa.

Dicoryne conferta (Alder, 1856)

Fig. 34E-J

Eudendrium confertum Alder, 1856: 354, pl. 12 (figs 5-8).

Dicoryne conferta: Allman, 1872: 226, 293, pl. 8. Jaderholm, 1909: 47, pl. 3 (fig. 6).

?Dicoryne sp.: Vervoort, 1972: 16.

Diagnosis. Colonies reaching a height of 25 mm growing on gastropod shells

occupied by hermits (including ?Anapagurus hendersoni Barnard). Hydrorhiza

reticulate, without spines, clothed with perisarc. Stem unbranched or branching

irregularly, unfascicled, increasing in diameter from base to distal end, clothed

with thick perisarc which terminates below hydranth. Branches leaving stem at

an acute angle. Perisarc wrinkled, especially near base. Hydranth with one

circle of 10—13 filiform tentacles.

Blastostyles borne on stem or direct from hydrorhiza, in the form of modi-

fied hydranths without mouth or tentacles but with a long and extensile hypo-

stome armed with nematocysts, bearing gonophores in a dense cluster below

hypostome, male and female on separate stems. Gonophores released as free-

swimming, ciliated sporosacs with two tentacles arising from proximal (i.e.

originally attached) end. Female containing two eggs.

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 34.

Clavopsella navis. A, part of female colony; B, mature female gonophore; C, female gonophore

after release of eggs, eggs segmenting; D, later stage with advanced planulae.

Dicoryne conferta. E, hydranth: F, female blastostyle; G, female gonophore in semi-

diagrammatic half-section; H, male gonophore; J, stems.

Abbreviations: ¢: endoderm; g: germ cells; p: perisarc; s: spadix; sc: subumbrellar cavity;

t: tentacle.

Scale: A and J in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 103

Nematocysts of at least two kinds:

(i) Small ones on hydranth tentacles, 4,8 «x 2,4 — 5,4 x 2,7 pn.

(ii) Large ones on blastostyle, 14,4 x 4,8 yu.

Variation. When the hydranth is contracted the perisarc around its base becomes

compressed and bulging, partly covering the hydranth body as a pseudo-

hydrotheca.

Although each female gonophore normally contains two eggs of equal

size placed in a plane at right angles to that of the tentacles, there may be only

one terminal egg or two of very unequal size.

Distribution outside South Africa. North Atlantic from the Arctic to the Medi-

terranean. Type locality: Cullercoats, U.K.

Distribution in South Africa. Agulhas Bank, from False Bay to Mossel Bay,

80-100 m. 34/18 (s), 34/21 (s), 34/22 (d)

Genus Rhizorhagium M. Sars, 1877

Syn. Wrightia Allman, 1872.

Parawrightia Warren, 1907.

Gravelya Totton, 1930.

Diagnosis. Stem erect, bearing a single terminal hydranth and, rarely, one or

two lateral ones as well, with firm perisarc continued over the base of the

hydranth body as a pseudohydrotheca but never investing the tentacle bases.

Hydranth with one whorl of filiform tentacles. Gonophores in the form of

fixed sporosacs, arising either from the hydrorhiza or from the stem.

Type species: Rhizorhagium roseum M. Sars, 1877.

One species only from South Africa.

Rhizorhagium robustum (Warren, 1907)

Fig. 35A—B

Parawrightia robusta Warren, 1907a: 187, figs 1, 2B, 3-4, pls 33-34.

Rhizorhagium robustum: Millard, 1966a: 452.

Diagnosis. Hydrorhiza creeping on weeds and sponges, reticular, giving rise

to erect stems reaching a maximum height of 12 mm, each bearing one terminal

hydranth and sometimes one or two lateral ones. Perisarc irregularly annulated

on stem, especially near base, continued over base of hydranth as a pseudo-

hydrotheca and terminating in a shallow groove below the tentacles, usually

with adherent silt. Hydranth with 13-22 tentacles, reaching a height of about

1,1 mm, not completely retractable into pseudohydrotheca.

Gonophores borne singly on stem below hydranth, pedicellate, completely

clothed in perisarc, with radial canals but no tentacle rudiments, male and female

on separate colonies. Male elongate-oval, female subspherical. Eggs developing

into planulae in situ.

Nematocysts 5,0 x 2,9 — 5,6 x 2,9 yu.

104 ANNALS OF THE SOUTH AFRICAN MUSEUM

Colour: endoderm red, other living parts translucent white, perisarce pale

to dark brown.

Distribution outside South Africa. South-east Madagascar. Type locality: Park

Rynie, South Africa.

Distribution in South Africa. East London to Natal, littoral. 33/27 (1), 30/30 (1)

Family Hydractiniidae

Diagnosis. Colonial hydroids with a stolonial habit and polymorphic hydranths,

typically with gastrozooids, gonozooids and dactylozooids. Skeleton of chitinous

perisarc or calcium limited to hydrorhiza and often forming spines. Hydranths

sessile and naked; with one or more whorls of filiform tentacles, if more than

one then concentrated around hypostome. Reproduction by fixed sporosacs or

medusae.

Medusa, when present, with four or more solid marginal tentacles not in

groups, mouth with four lips elongated to form four or eight simple or slightly

branched oral arms with terminal clusters of nematocysts, four radial canals,

with gonads on interradial walls of stomach or on proximal portions of radial

canals as well.

Introduction. Among the Hydractiniidae the subdivision into genera has been

the subject of much discussion. The arguments cannot be reproduced here, but

the works of Stechow (1923c), Kramp (1932), Iwasa (1934), Rees (1962) and

Bouillon (1971) may be consulted. In this paper the definitions of Bouillon

(1971: 351) for the genera Hydractinia, Podocoryne and Stylactis are adopted.

In addition the genera Clavactinia and Hydrocorella are represented in South

Africa.

All the Hydractiniidae have stolonial colonies. They are also polymorphic,

and there occur gastrozooids, gonozooids, usually smaller than the gastrozooids

and with fewer tentacles, and dactylozooids, often confined to the edge of the

colony. Dactylozooids may take the form of spiral zooids or tentaculozooids.

The nature of the hydrorhiza has been the cause of most of the dissension

on generic limits. It arises as a system of perisarc-covered stolons which anasto-

mose to form a reticulum, and tend to coalesce with one another. In Stylactis

the tubes are usually separate and are always covered with firm perisarc. In

Hydractinia, Podocoryne and Clavactinia the superficial layer of perisarc over the

coalesced tubes tends to disappear leaving a layer of naked ectoderm over the

surface of the mat-like hydrorhiza. In young colonies, or at the edge of older

ones, this process may be incomplete, so that there is then liable to be confusion

with Stylactis, but as Kramp (1932) states, it is the potentiality for producing the

layer of naked coenosarc which is important. Horny spines arising from the

perisarc protrude through the coenosarc in many species.

In Hydrocorella the hydrorhiza secretes a calcareous skeleton which rises

into a fantastic arrangement of spines and pillars, the whole covered by naked

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 105

Fig-3).

Rhizorhagium robustum. A, stem with two hydranths; B, two hydranths, one with a sporosac,

redrawn from Warren (1907a, as Parawrightia robusta).

Clavactinia multitentaculata, sp. nov. C, colony with gastrozooids, male gonozooids and spines,

from holotype: D, spiral zooids from holotype; E and F, l.s. and t.s. young female

gonophore; G, t.s. male gonophore from holotype.

Scale: A, B and C in mm, the rest in mm/10.

106 ANNALS OF THE SOUTH AFRICAN MUSEUM

coenosarc as in the above-mentioned genera. A calcareous skeleton is unusual

among the hydroids and according to Stechow (1925a) provides a link with the

Stylasteridae.

Most of the genera have a single whorl of tentacles on the hydranth but,

among these, species with many tentacles may have alternate ones slightly dis-

placed, giving the appearance of two closely alternating rows. In Clavactinia

there are several such whorls and, as was mentioned on p. 70, this is probably

a primitive condition for the family.

Reproduction is by fixed sporosacs or free medusae and all stages between

these two extremes may occur. It has been claimed that because of intermediate

conditions it is not possible to separate genera on this basis. However, it is felt

that there is a big difference between the highly developed medusae of a typical

Podocoryne and the degenerate medusae found in some species of Hydractinia.

The intermediate stages are, as elsewhere in this work, classified as “sporosacs’.

One of the most interesting features of the Hydractiniidae is the adoption

of an epizootic life on the shells of hermits or gastropods. The advantage of this

type of life appears to be the ability to inhabit niches otherwise not available,

e.g. Hydractinia kaffraria in the mud of estuaries and H. altispina in sandy tidal

pools, where the hydranths are not only provided with transport but are held

clear of the substratum. A list of hosts carrying epizoites will be found on p. 23.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Hydrorhiza with calcareous skeleton a Be e a Hy arte pons

— Hydrorhiza without calcium in the skeleton be x. a ; 2;

2. Gastrozooids with several whorls of tentacles .. Clovacnon p. 106

— Gastrozooids with only one whorl of tentacles, which may be ‘displaced alter-

nately to form two apparent whorls Re: ae a ag 3

3. Gonozooids producing free medusae 2 ae Sie ie [Podocorynel

— Gonozooids producing fixed sporosacs Bs se

4. Hydrorhiza covered with a layer of naked coenosarc .. < Beene p. 108

Hydrorhiza reticular, the tubes covered with firm perisarc; no naked coenosarc

Stylactis p. 118

Genus Clavactinia Thornely, 1904

Diagnosis. Hydrorhiza of anastomosing perisarc-covered tubes coalesced into a

basal incrusting layer and covered by a layer of naked coenosarc, often bearing

spines. Gastrozooids with several close-set whorls of tentacles. Gonophores in

the form of fixed sporosacs.

Type species: Clavactinia gallensis Thornely, 1904.

One species only from South Africa.

Clavactinia multitentaculata sp. nov.

Fig. 35C-G

Hydractinia sp. Millard, 1968: 255.

Holotype. A male colony growing on the shell of the gastropod Melapium

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 107

lineatum (Lamarck) occupied by a hermit, Dardanus arrosor (Herbst). Off

Natal, approximately 29°54’S/31°11’E, 99 m. Cat. no. SAM—H389.

Description of holotype. Hydrorhiza a network of coalesced perisarcal tubes

covered by a layer of free coenosarc, giving rise to numerous smooth, hollow

spines 0,4—-0,6 mm in length.

Gastrozooids with many tentacles in ae close-set verticils. The number

of tentacles varies according to the size (and presumably the age) of the gastro-

zooids. In the larger polyps they are almost impossible to count. Counts made by

cutting off the tentacles and counting the tips yielded numbers of 65, 84 and 91.

More approximate counts gave numbers ranging from 42-++ to 73. The normal

adult number is thus well over 40. Larger gastrozooids are longitudinally

marked, shown by sections to be due to ridging of the endoderm.

A few spiral zooids present in local areas around the opening of the host

shell.

Male gonozooids smaller and more slender than gastrozooids, with mouth

and 7-13 tentacles, bearing 3-4 gonophores in the form of fixed sporosacs.

Sections show no endodermal ridging. Sporosac spherical, reaching 0,66 mm in

length and 0,68 mm in diameter, with four radial canals and a circular canal.

Spadix central. Spermatogenic cells divided into four compartments alternating

with the radial canals. Sections reveal the presence of a thickened and inturned

‘umbrella’ margin and a depressed velar plate. The largest sporosacs are so

swollen with spermatogenic cells that the cavities of the spadix and the radial

canals are not visible. These structures are, however, quite distinct in the younger

ones.

Information from other specimens. Colonies other than the holotype have been

found on the gastropods Astraea tayloriana (Smith) and Turbo sarmaticus

Linnaeus.

Female gonozooids are similar to the male, though with only 5-8 tentacles.

Each bears two sporosacs, one large and one small, at about two-thirds of its

length. Sporosac spherical, the largest reaching 0,70 mm in length and 0,68 mm

in diameter, though possibly not quite mature, with four radial canals and a

circular canal and four minute tubercles at margin. Spadix central, with a

quadrate lumen, bearing a single layer of eggs arranged in four compartments

alternating with the radial canals. Eggs small and numerous, estimated to be

about 300 in number (about 20 longitudinal rows with about 15 to a row).

This colony with no spiral zooids, but with a few scattered tentaculozooids.

Spines not so numerous as in the holotype.

A living male colony showed that mature Sears reach 8,0 mm

when fully extended; young hydranths have only one whorl of tentacles but

the number increases with age. Extended gonozooids reach a maximum length

of 3,2 mm; those with young gonophores have as many as 16 tentacles, but

those with mature gonophores often have only one or two or none at all,

apparently due to reproductive exhaustion.

108 ANNALS OF THE SOUTH AFRICAN MUSEUM

Nematocysts of two kinds:

(i) Desmonemes, 5,4 x 3,0 — 7,2 x 3,6 u. Capsule oval; abundant on tentacles.

Thread in four coils when discharged.

(ii) Microbasic euryteles, 9,0 x 2,4 — 13,8 x 4,2 uw. Capsule banana-shaped;

abundant on hypostome.

Colour: orange throughout.

Remarks. C. multitentaculata differs from C. gallensis, the type species of

Clavactinia, in the larger size of the gastrozooids and greater number of tentacles,

in the presence of radial canals in the sporosacs and in the greater number of

eggs in the female sporosac.

Distribution. Endemic to South Africa.

Distribution in South Africa. False Bay and Natal only with certainty, in 15-99 m,

but probably more widespread. 34/18 (s), 29/31 (s)

Genus Hydractinia van Beneden, 1841

Diagnosis. Hydrorhiza of anastomosing perisarc-covered tubes coalesced into a

basal incrusting layer and covered by a layer of naked coenosarc, often bearing

spines. Gastrozooids with tentacles in one whorl (or rarely two closely alter-

nating whorls). Gonophores in the form of fixed sporosacs.

Type species: Hydractinia lactea van Beneden. 1844.

KEY TO SPECIES

(Doubtful species not included, for these see p. 115)

1. Spines present, smooth se ae ae 5 ar o a ae Pere

Spines absent . aes : 3

2. On Thais squamosa. Spines reacting 1 mm. Sporosacs Tihont tentacles aaale divided

into 4 compartments, female with about 32 eggs in about 4 tiers ne H. altispina

— On hermit shells. Spines reaching 0,6 mm. Sporosacs without tentacles, male not

divided, female with 5—13 eggs in 2 tiers : H. diogenes

— On Nassa speciosa. Spines reaching 0,4 mm. Sporosacs with 4-8 marginal tentacles and

external marsupium, male divided into 4 compartments, female with 20-40 eggs in

3-6 tiers = ie os H. marsupialia

3. On Nassa kraussiana. Gasttoreoins ee Penele sporosacs with 21-32 eggs in about

4tiers .. S H. kaffraria

— On weed. Gastrozooid mouth blocked by endoderm. Female sporosacs with over 50

eggs in about 7 tiers A ee ie e a; ee ae H. canalifera

Hydractinia altispina Millard, 1955

Frontispiece; Fig. 36A—D

?Hydractinia sp. Broch, 1914: 24 (material from South West Africa).

Hydractinia altispina Millard, 1955: 215, fig. 1.

Diagnosis. Colonies epizootic on the gastropod Thais squamosa (Lamarck).

Hydrorhiza covered with a layer of naked coenosarc, bearing spines, gastro-

zooids and gonozooids. Spines smooth, hollow and long, 0,4-1 mm. Gastro-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 109

zooids reaching 4 mm, with 5-12 tentacles, long and short alternating. Gono-

zooids much smaller than gastrozooids, reaching 0,8 mm, with 3-5 very short

tentacles, bearing several sporosacs usually on the basal region. No dactylo-

zooids.

Sporosacs with four radial canals and a circular canal, but no marginal

tentacles, bearing the sexual products around a central spadix, male and female

on separate colonies. Male spherical, reaching 0,4 mm in diameter, with sperma-

togenic cells divided into four compartments separated by the radial canals.

Female oval, reaching 0,5 mm in diameter, containing about 32 eggs in about

four tiers.

Colour: Colony orange throughout, gastrozooids sometimes paler.

Nematocysts: desmonemes. 6,0 < 3,6 uw; microbasic euryteles, 8,4 x 2,4 —

13,8 x 5,4 uw.

Distribution. Endemic to South Africa. Type localities: False Bay and Lambert’s

Bay.

Distribution in South Africa. Liideritz Bay to False Bay, littoral to 24 m. 26/15

(1), 28/16 (s), 32/18 (I, s), 33/18 (1), 34/18 (J, s)

Hydractinia canalifera Millard, 1957

Fig. 36E-G

Hydractinia canalifera Millard, 1957: 179, fig. 1.

Diagnosis. Colony growing on weed. Hydrorhiza covered with a layer of naked

coenosarc in centre of colony, of separate perisarc-covered tubes at periphery,

bearing gastrozooids, gonozooids and tentaculozooids, but no spines. Gastro-

zooid reaching 3,2 mm, with 10-14 tentacles, with mouth and hypostome plug-

ged with endodermal tissue; hydrocaulus with a strongly marked, narrow,

central lumen. Gonozooid smaller than gastrozooid, reaching 1,3 mm, with

6-9 tentacles, bearing 4-5 sporosacs on upper half of hydrocaulus. Tentaculo-

zooids sparse, scattered.

Female sporosac ovoid, reaching 0,5 mm in diameter, with four radial

canals and a circular canal (visible only when young), no tentacle rudiments,

containing over 50 eggs in about seven tiers around a central spadix. Male

Sporosac unknown.

Distribution. Endemic to South Africa.

Distribution in South Africa. Known only from the type locality: Clovelly,

False Bay, littoral. 34/18 (1)

Hydractinia diogenes Millard, 1959

Fig. 37A—D

Hydractinia diogenes Millard, 1959a: 305, fig. 2. Millard & Bouillon, 1974: 20.

Diagnosis. Colonies epizootic on shells of the hermit, Diogenes costatus (Fabr.).

Hydrorhiza covered with a layer of naked coenosarc, bearing spines, gastro-

110 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 36.

Hydractinia altispina. A, various zooids: two gastrozooids, two female gonozooids, one male

gonozooid and two spines; B, microbasic eurytele and desmoneme; C, t.s. male sporosac;

D, I.s. female sporosac.

Hydractinia canalifera. E, part of colony, with two gastrozooids, two female gonozooids and

a tentaculozooid; F, l.s. young female sporosac showing radial and circular canals;

G, l.s. mature female sporosac.

Scale: A in mm, B in mm/100, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA Py

zooids, gonozooids and spiral zooids. Spines smooth, hollow and of medium

length (0,5-0,6 mm). Gastrozooids 2-3 mm in length, with 10-26 tentacles.

Gonozooids generally smaller than gastrozooids, with 5-15 tentacles often

reduced to mere stumps, bearing a ring of up to six sporosacs. Spiral zooids

sometimes present, 2-3 mm in length, with terminal battery of nematocysts.

Sporosacs spherical, reaching 0,5 mim in length and breadth, male and

female on different colonies, with four radial canals (but visible in female only)

and a circular canal, bearing the sexual products around a central spadix.

Female containing 5—13 eggs in two tiers. Male not divided into segments.

Nematocysts: desmonemes, 5,0 < 3,5 uw; microbasic euryteles, 9,0 x 4,0 yw.

Distribution. Endemic to South Africa.

Distribution in South Africa. East coast, Inhaca to Morrumbene (type locality),

in shallow water. 26/32 (s), 23/35 (s)

Hydractinia kaffraria Millard, 1955

Fig. 37E-G

Hydractinia kaffraria Millard, 1955: 217, fig. 2. Millard, 1966a: 457, fig. 6. Schmidt, 1972:

Saepla iG:

Diagnosis. Colonies epizootic on the gastropod Nassa kraussiana (Dunker).

Hydrorhiza covered with a layer of naked coenosarc, bearing gastrozooids,

gonozooids and tentaculozooids, but no spines. Gastrozooid reaching 2,0 mm,

with 8-15 tentacles. Gonozooid smaller than gastrozooid, reaching 1,1 mm,

with 5-12 tentacles, bearing sporosacs below the tentacles. Tentaculozooids

sparse and scattered, reaching 3,0 mm.

Sporosacs subspherical, with four radial canals and a circular canal, with

rudimentary marginal tentacles, bearing the sexual products around a central

spadix, male and female on separate colonies. Male reaching 0,6 mm in diameter,

spermatogenic cells not divided into compartments. Female reaching 0,9 mm

in diameter, containing 21-32 eggs in about four tiers.

Observations on living material. Although the sporosacs have some medusoid

structures, the sexual products are released while they are still attached and there

is no free-swimming life. Powerful pulsations of the whole bell in the male,

and of the area around the aperture in the female, expel the spermatozoa and

eggs respectively. This species is easily kept in aquarium tanks,

Distribution outside South Africa. Red Sea. Type localities: Breede River and

Keiskama River estuaries, South Africa.

Distribution in South Africa. In estuaries only, from the Breede River on the

south coast to Durban Bay in Natal. 34/20 (s), 34/23 (s), 33/25 (s), 33/26 (s),

33/27 (s), 29/31 (s)

112 ANNALS OF THE SOUTH AFRICAN MUSEUM

Pigi 3.

Hydractinia diogenes. A, part of female colony; B, t.s. female sporosac showing radial canals;

C, l.s. female sporosac showing circular canal; D, l.s. ripe male sporosac.

Hydractinia kaffraria. E, \.s. young female sporosac; F, l.s. male sporosac; G, part of colony

with gastrozooid, tentaculozooid and female gonozooid.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 113

Hydractinia marsupialia sp. nov.

Fig. 38

Podocoryne carnea: Ritchie, 19076: 523. Millard, 1966a: 461.

?Hydractinia parvispina: Vanhoffen, 1910: 291.

Hydractinia carnea: Millard, 1957: 181.

Holotype. A female colony on Nassa speciosa from Table Bay. Cat. no. SAM-—

H1854.

Paratypes. Nine other colonies, including both male and female, on the same

host and from the same locality. Cat. no. SAM-H1855.

Description of type series. Colonies epizootic on the gastropod Nassa speciosa

Adams. Hydrorhiza a network of perisarc-covered tubes which is open in

young colonies but in older ones is coalesced to form an incrustation covered

with a layer of naked coenosarc; bearing spines, gastrozooids and gonozooids.

Spines smooth and short, reaching a maximum height of 0,4 mm, but more

often only 0,2 mm or less; occasionally absent, especially in young colonies.

Gastrozooids reaching a maximum height of 1,9 mm (preserved), with

8-16 tentacles, with no perisarcal collar.

Gonozooids smaller than gastrozooids, reaching a maximum height of

0,8 mm (preserved), with 5—9 tentacles, bearing a circle of up to six gonophores.

Gonophores round or oval, reaching a maximum length of 0,7 mm and a

maximum diameter of 0,6 mm, with 4-8 marginal tentacles reaching 0,18 mm

in length, each with a pigmented spot at base, with four radial canals and a

circular canal. Sexual products discharged into, and retained for a while within,

a marsupium formed by the perisarcal coating of the gonophore. Medusoid

remaining attached after evacuation of sexual products from marsupium.

Female with 20-40 eggs arranged in 3-6 tiers. Male with four groups of sperma-

togenic cells alternating with the radial canals.

Colour: creamy white, marginal bulbs of medusoids dark red.

Nematocysts of two kinds:

(i) Long-oval capsules, 7,2 x 2,7 — 10,2 x 3,6 pu.

(ii) Short-oval capsules, 5,4 x 3,0 yu.

Histology. Sections through a mature male medusoid with the spermatogenic

cells extruded into the marsupium show several interesting features. The ecto-

derm lining the subumbrellar cavity (entocodon) is thickened and contains

branching mesogloeal lamellae bearing muscle fibres. The latter are presumably

used to expel the sexual products and are similar to those found in the Myrio-

thelidae. This whole layer is much thinner before extrusion when it is stretched

by the bulging gonads and the lamellae are then scarcely recognizable. The

stomach is well developed and quadrangular; during extrusion the tip of the

hypostome is squeezed out into the marsupium and its cavity closed by pressure

in the region of the bell margin. Remains of the ruptured velum are clearly

visible.

114 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 38.

Hydractinia marsupialia sp. nov. A, Male colony from holotype; B, I.s. ripe male sporosac

compiled from sections and whole mounts and passing through a radial canal on left;

C, ripe male sporosac; D, ripe male sporosac with spermatogenic cells extruding into

marsupium; E, spent male sporosac; F, ripe female sporosac from paratype.

Abbreviations: c: capsule; cc: circular canal; ec: ectoderm with muscle layer; en: endoderm;

g° gonad; m: marsupium; rc: radial canal; t: tentacle; v: remains of velum.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA LS

The structure of the female gonophore is similar, but no stages with eggs

extruded into the marsupium occur. In the oldest specimens the velum is rup-

tured and the tentacles extended into the marsupial cavity. The eggs are arranged

in four groups although these are not so clearly demarcated as in the male.

The muscle layer of the entocodon is clearly visible in young gonophores but

stretched and thin in older ones. ;

Remarks. This species was previously ascribed to Podocoryne carnea (Millard

1957, 1966a) when gonophores full of sexual products and young medusae

without gonads were found on the same colony. From a further study it is now

clear that the medusoids with free tentacles are individuals which have released

their sexual products but have remained attached to the gonozooid. There is

thus no evidence that the medusae are freed, and the material must be removed

from the genus Podocoryne.

The condition is similar to that described for Hydractinia proboscidea

(Hincks 1868) where also the sexual products are extruded and held temporarily

within the perisarcal covering. H. proboscidea differs in the absence of spines

and lack of differentiation between gonozooids and gastrozooids.

Distribution. Endemic to South Africa.

Distribution in South Africa. Saldanha Bay to Algoa Bay, 4-82 m. ?Inhaca.

Type locality: Table Bay. 33/17 (s), 33/18 (s), 34/18 (s), 34/21 (s), 34/22 (s),

34/23 (s), 33/25 (s), 33/26 (s), 34/25 (s), 226/32 (s)

Doubtful species

Hydractinia pacifica Hartlaub, 1905

Hydractinia pacifica: Stechow, 1925a: 408.

Remarks. Stechow records this species from Algoa Bay. However, his colony was

male, and the distinctive features of H. pacifica rest in the female sporosac, which has

only one egg surrounded by a branching spadix. No Hydractinia with such female

sporosacs has been recorded from South Africa and Stechow’s record should be drop-

ped from the literature.

The host snail (Phos plicosus—Nassa speciosa) and the number of tentacles in

gastrozooid and gonozooid suggest that Stechow’s material was a spineless variety of

Hydractinia marsupialia.

Genus Hydrocorella Stechow, 1921

Diagnosis. Hydrorhiza with a calcareous skeleton developing small spines and

large pillar-shaped processes, covered by a layer of naked coenosarc. Gastro-

zooids with one whorl of tentacles. Gonophores in the form of fixed sporosacs.

Type species: Hydrocorella africana Stechow, 1921.

One species only from South Africa.

116 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hydrocorella africana Stechow, 1921

Frontispiece; Fig. 39

Hydrocorella africana Stechow, 1921c: 30. Stechow, 1925a: 409. Millard, 1966a: 458, fig. 7.

Diagnosis. Colonies epizootic on shells of gastropods and hermits. Hydrorhiza

secreting a calcareous skeleton which is covered by a layer of naked coenosarc

bearing gastrozooids, gonozooids and tentaculozooids. Skeleton produced into

conspicuous longitudinally ridged processes of two grades: the larger reaching

5 mm or more and bearing hydranths on the surface, the smaller 0,5-1,0 mm.

Gastrozooids reaching 3 mm in length when expanded, with 5—12 tentacles,

of which one or two are usually much longer than the others. Tentaculozooids

situated round shell aperture, with terminal battery of nematocysts, not always

present. Gonozooids reduced, about 0,5 mm in length, with about six rudimen-

tary tentacles, bearing several sporosacs.

Sporosacs spherical, with no radial or circular canals and no tentacles,

male and female on separate colonies. Male reaching 0,3 mm in diameter,

bearing the sexual products around a central spadix. Female reaching 0,6 mm

in diameter, bearing a single egg which is later surrounded by hollow out-

growths from the short, basal spadix. Planula gourd-shaped, developing in situ.

Colour: skeleton chalky white, hydranths creamy white to pale orange,

sporosacs orange.

Nematocysts of two kinds:

(i) Microbasic euryteles, 7,2 x 2,7 — 11,4 x 4,8 pu.

Gi) Desmonemes, 4,5 x 2,4 — 6,6 x 3,0 pu.

Variation. Although there is much variation in the shape and size of the skeletal

processes, the species is easily recognized by the chalky white skeleton. In young

colonies only the small processes are present and the colony is low, spreading

and Hydractinia-like in appearance. Later the skeleton becomes thicker and

the larger processes develop, giving a grotesque appearance to the whole.

There may be as many as six large processes on one host, and they often show a

tendency to project forwards over the mouth of the shell in the line of movement

of the host. The processes are usually longitudinally ridged and star-shaped in

section, but there may be fusion between two or more, compression in one

plane or other irregularities. In old colonies the smaller processes may form

compressed and curved plate-like structures arching over the gonozooids and

the developing planulae. The latter are thus imprisoned until they become free

from the gonozooids and able to escape by amoeboid movements.

The presence of one or two extra long tentacles on the gastrozooid is very

typical. The tentacles usually arise in one whorl, but sometimes one or more

appear to arise at a lower level than the rest.

There seems to be no specificity in the choice of host, and a considerable

number of host gastropods and hermits has been recorded (see p. 23). Often

the host is so overgrown that it is impossible to identify it.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA. 7

0 Mess sais

ees Senet ae

c ry 9

Se, c

| SS

OT ee ee oe oe

F-G

Fig. 39.

Hydrocorella africana. A, colony completely covering shell of hermit; B, section through

colony and host shell showing calcareous processes and contracted hydranths; C, gastro-

zooids; D, gonozooids, two female and one male; E, planula; F, t.s. female sporosacs

of different ages; G, l.s. female gonozooid and sporosac; H, nematocysts, from left to

right: microbasic eurytele discharged and undischarged, desmoneme.

Scale: A, B and C in mm, H in mm/100, the rest in mm/10.

118 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution. Endemic to South Africa. Type locality: ‘South Africa’.

Distribution in South Africa. Orange River mouth to Durban, littoral to 500 m.

Common in shallow dredgings round the south-west Cape. 28/16 (s), 30/17 (1),

32/17 (s), 33/17 (s), 33/18 C1, s), 34/18 (s), 34/19 (s), 35/19 (s), 34/20 (s), 35/20 (s),

34/21 (s), 34/22 (d), 34/23 (d), 35/23 (vd), 34/24 (d), 29/31 (s)

Genus Stylactis Allman, 1864

Syn. Halerella Stechow, 1922.

Diagnosis. Hydrorhiza of anastomosing perisarc-covered tubes which may bear

spines. No superficial layer of naked coenosarc. Gastrozooids with tentacles

in one whorl (or rarely two closely alternating whorls). Gonophores in the form

of fixed sporosacs, borne on blastostyles.

Type species: Stylactis inermis Allman, 1872.

One doubtful species from South Africa.

Doubtful species

?Stylactis siphonis (Stechow, 1921)

Stylactella siphonis Stechow, 19216: 224.

Halerella siphonis: Stechow, 1925a: 407, fig. 2.

Diagnosis. Colonies epizootic in the siphon of a gastropod. No spines. Gastrozooids

reaching 0,8 mm, with a broad base and 8-10 tentacles. Reproduction unknown.

Remarks. Stechow reported this species from 500 m, south of Plettenberg Bay. It has

not been rediscovered, and Stechow’s description is so brief that the systematic posi-

tion is in doubt. Examination of a whole mount from Stechow’s collection has added

nothing further to our knowledge. Stechow records the host gastropod as Sipho

islandicus, but this species is not known in South African waters.

Family Cytaeidae

Diagnosis. Colonial hydroids with a stolonial habit but no polymorphism.

Hydrorhiza of anastomosing perisarc-covered stolons which are not incrusted

and are without spines. Hydranths sessile and naked, but often with a cup-

shaped collar of perisarc around base, with one whorl of filiform tentacles and

a conical hypostome. Gonophores borne directly on the hydrorhiza, in the form

of fixed sporosacs or medusae.

Medusa, when present, deep bell-shaped, with simple mouth, four solid mar-

ginal tentacles, unbranched oral tentacles on mouth-rim and four unbranched

radial canals; without ocelli; gonads interradial or forming a continuous ring.

Introduction. This is a small family created originally for the medusa genus

Cytaeis. The hydranth generation was unknown until 1931, but since then

several life histories have been worked out. The family has been revised and/or

discussed by Kramp (1932), Rees (1956b, 1962) and Uchida (1964).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 119

The hydranth generation is very similar to that of the Hydractiniidae and,

4s in this family, shows a preference for an epizootic life on gastropod shells.

However, unlike the Hydractiniidae, the hydrorhizal tubes do not coalesce and

become incrusted, spines never occur and there is no polymorphism. A collar

or vase-like tube of perisarc typically surrounds the base of the otherwise naked

hydranth, and this does not occur in the Hydractiniidae. As in some species of

Hydractinia alternate tentacles of the hydranth may be displaced, giving the

appearance of two closely alternating whorls.

One of the most distinctive features of the family is the fact that the gono-

phores are borne direct on the hydrorhiza and not on hydranths or on gono-

zooids. These may develop into free-swimming medusae in Cytaeis or may

remain attached as sporosacs or degenerate medusae in Perarella, a genus

which was re-established by Rees (19565).

The adult medusa is of simple construction and shows resemblances to

that of the Hydractiniidae and the Bougainvillidae. It differs from the Hydracti-

niidae in the better defined oral tentacles, and from the Bougainvilliidae by the

insertion of the oral tentacles on the mouth-rim rather than just above it.

Uchida (1964) considers that the Bougainvilliidae could have arisen from the

Cytaeidae by the branching of the oral tentacles and the increase in number

and clustering of the marginal tentacles.

In the type species of Cytaeis, C. tetrastyla, Kramp (1959) has reported the

budding-off of hydranths from the stomach wall of the medusa. The further

history of these buds is unknown, nor is it established whether there is any

fixed hydranth stage.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Producing free medusae .. # - we ies at Bs Cytaeis p. 119

— Producing fixed sporosacs are te i Sy. xe Eee [Perarella]

Genus Cytaeis Eschscholtz, 1829

Diagnosis. Gonophores developing into free medusae. Adult medusa with

characters of family.

Type species: Cytaeis tetrastyla Eschscholtz, 1829.

One hydranth species only from South Africa.

Cytaeis nassa (Millard, 1959)

Fig. 40

Podocoryne nassa Millard, 1959a: 307, fig. 3.

Cytaeis nassa: Rees, 1962: 390, figs 8-9, pl. 11. Vervoort, 1967: 26, fig. 3, pl. 3 (fig. 2). Millard

& Bouillon, 1973: 31, pl. 5.

Diagnosis. Colony epizootic on shells of gastropods of the genus Nassa. Hydro-

rhiza reticular, following the grooves of the host shell. Hydranths columnar,

120 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 40.

Cytaeis nassa. A, colony on host shell; B—D, stages in development of medusa-bud.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 121

widest near base but narrowed at origin from hydrorhiza, reaching a maximum

height of 2,5 mm, with conical hypostome and 8-16 tentacles in two closely

alternating whorls, often surrounded at base by a cup-like expansion of peri-

sarc.

Gonophore arising separately from hydrorhiza on slender pedicel, pear-

shaped when young, globular when mature, completely enveloped by mem-

branous perisarc. Medusa at liberation deep bell-shaped, reaching 0,5 mm in

depth, with four radial canals, four perradial marginal bulbs bearing tentacles,

tubular hypostome with four oral tentacles armed with distal nematocyst

clusters. Adult medusa unknown.

Nematocysts of two types: heteronemes, 8,1 x 3,1 wu, and ?desmonemes,

6,3 < 3,6 LW.

Distribution outside South Africa. Red Sea (on Nassa arcularia and N. fenestrata),

Madagascar (on N. arcularia and N. albescens), Seychelles, Mauritius.

Distribution in South Africa. Inhaca Island, Mogambique (type locality), littoral,

on N. fenestrata and N. coronata. 26/32 (1), 25/32

Family Pandeidae

Diagnosis. Colonial hydroids with a stolonial habit. Hydranths with one whorl

of filiform tentacles or with tentacles absent. Perisarc of variable development

or completely absent. Producing free medusae.

Adult medusa without oral tentacles but with four simple or crenulated

oral lips, four radial canals, hollow marginal tentacles, with or without ocelli.

Introduction. The Pandeidae is an important medusa family in which the

hydranth generation is usually inconspicuous, has little to distinguish it from

several other families and has practically no diagnostic characters. In many

species the hydranth is still unknown. Among those which are known Leuckar-

tiara and Hydrichthys are fairly easily recognized; others must be reared to the

medusa stage for identification to genus or even family level.

So far as is known the hydroid generation is always stolonial, with hydranths

rarely branching once or twice only.

The hydrorhiza is usually reticular and covered by perisarc, but in the

aberrant parasitic genus Hydrichthys the hydrorhiza is expanded and plate-

like, capable of eroding the flesh of the host, and is reminiscent of the naked

coenosarc encountered in the Hydractiniidae.

The degree of development of perisarc varies considerably. It is entirely

absent in Hydrichthys, and limited to the hydrorhizal tubes in Pandea conica.

In both these genera the hydranth is sessile. In Amphinema and Leuckartiara

the hydranth is borne on the summit of a distinct hydrocaulus. In Amphinema

the perisarc continues on to the hydrocaulus and terminates below the hydranth

body. In Leuckartiara it continues over the base of the hydranth as well, where

it forms a swollen and gelatinous pseudohydrotheca similar to that found in

122 ANNALS OF THE SOUTH AFRICAN MUSEUM

some Bougainvilliidae. In Hydrichthys the hydranths are devoid of tentacles,

apparently a secondary condition associated with the parasitic mode of life.

The adult medusa is characterized by its four-lipped mouth without

oral tentacles but usually with elaborately folded margins, and by its large and

usually laterally compressed marginal bulbs. Unlike the Bougainvilliidae the

marginal tentacles are hollow.

Both medusa and hydranth generations show much diversity and, as

suggested by Uchida (1964), the family will undoubtedly need subdivision

once the life-histories are better known.

KEY TO GENERA

[Genera in which the hydranth generation is unknown in South Africa are bracketed.]

1. Hydranth generation parasitic on fish, without tentacles se: Hydrichthys p. 122

— Hydranth generation not parasitic, but often epizootic on gastropods and other

hosts. Tentacles present = a = - af Ma ce fe Z

2. Perisarc continued over base of hydranth as a pseudohydrotheca Leuckartiara p. 123

— Perisarc not covering hydranth . ee ‘ Ma; a bs 3

3. Hydranths sessile, with no distinct hydrocaulus .. i BE .. [Pandea]

— Hydrocaulus well developed, longer than hydranth 56 ie: [Amphinema]

Genus Hydrichthys Fewkes, 1888

Diagnosis. Colony parasitic on fish. Hydrorhiza expanding to form a plate-

like layer without covering perisarc and, in at least some species, capable of

eroding the underlying fish tissue. Hydranths without tentacles. Gonophores

developing into free medusae with two opposite marginal tentacles at liberation,

two or four at a later stage. Adult medusa unknown.

Type species: Hydrichthys mirus Fewkes, 1888.

One species only from South Africa.

Hydrichthys boycei Warren, 1916

Fig. 41E-H

Hydrichthys boycei Warren, 1916: 172-185, fig. 12, pls 17-20. Kramp, 1921: 13, 15. Millard,

1959a: 309.

Diagnosis. Colony parasitic on fish of the species Ambassis safgha (Forskal)

(syn. A. natalensis), Chaetodon lunula (Lacépéde), and Mugil sp.

Hydranth without tentacles, naked, reaching 2,5 mm in height, with a band

of nematocysts around mouth. Medusa-buds borne on hydrorhiza and on

hydranth in clusters, the hydranth when fully developed becoming very large

and often branched.

Medusa at liberation with four radial canals and a circular canal, a quad-

rihedal mouth and two massive and opposite marginal bulbs. No ocelli. Slightly

older medusa with two very long marginal tentacles.

Colour: reddish.

Nematocysts of one type only, possibly stenoteles, 9,1 x 3,6 wu.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 123

Remarks. In this species the lower surface of the hydrorhiza is capable of eroding

the tissues of the host and can send haustorium-like outgrowths into the flesh.

The hydranths can then apply their open mouths to the damaged surface and

tap the blood vessels.

Warren distinguished between normal feeding hydranths and ‘gonostyles’

bearing medusae, some of the gonostyles being very large and fleshy and

apparently without a hypostome. In my material there is no essential difference

between the infertile and fertile hydranths. The medusa-buds develop on the

body of the hydranth and gradually increase in number, the attachments of the

clusters becoming drawn out as lateral branches. At the same time the hydranth

increases in size and girth. In this sample at any rate the hypostome is always

retained though often obscured by the wealth of medusa-buds. It is possible

that it may atrophy in older individuals.

The genus Hydrichthys is included in the Pandeidae on the structure of the

young medusa, although no adult medusae with ripe gonads are known.

Distribution. Endemic to South Africa. Type locality: Durban Bay.

Distribution in South Africa. Durban area only. 29/31

Genus Leuckartiara Hartlaub, 1914

Diagnosis. Colony stolonial. Hydrorhiza reticular. Stem unbranched or sparingly

branched, unfascicled, covered with perisarc which extends as a gelatinous

pseudohydrotheca over the base of the hydranth, but does not invest the bases

of the tentacles. Hydranth with one whorl of filiform tentacles and a conical

hypostome. Gonophores borne on stem or hydrorhiza, completely invested in

perisarc, developing into free medusae.

Medusa with apical process; with large stomach attached to radial canals

by ‘mesenteries’; mouth with much-folded or crenulated lips; gonads interradial,

horseshoe-shaped, with folds directed perradially; radial canals broad and rib-

bon-like, often with jagged edges; with numerous marginal tentacles with elon-

gated laterally compressed marginal bulbs; often with rudimentary tentacles.

Type species: Geryonia octona Fleming, 1823.

One hydranth species only from South Africa.

Leuckartiara octona (Fleming, 1823)

Fig. 41A—D

Geryonia octona Fleming, 1823: 298.

Perigonimus vestitus f. radicans Vanhoffen, 1910: 286, fig. 11.

Leuckartiara octona: Rees, 1938: 12, figs 3-5. Russell, 1953: 188, figs 91-96, pl. 11 (figs 5-6),

pl. 12 (fig. 3), pls 30-31. Rees, 1956a: 347. Millard, 1957: 182. Kramp, 1965: 30.

Diagnosis. Colonies epizootic on the shells of gastropods, reaching a maximum

height of 5 mm. Stem increasing in diameter from base to distal end, bearing

a terminal hydranth and occasionally 1-3 lateral ones as well. Perisarc firm,

124 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 41.

Leuckartiara octona. A, hydranths bearing medusa-buds; B—D, medusa-buds of different ages.

Hydrichthys boycei. E.and F, medusa-buds at liberation, redrawn from Warren (1916)

G, various zooids from colony; H, older medusa, redrawn from Warren (1916).

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF £ JTHERN AFRICA | Bis

often annulated or wrinkled, especially at base, e»panding to form a gelatinous

pseudohydrotheca over base of hydranth, usualiy covered with adherent silt.

Hydranth with 6-12 tentacles.

Medusa-buds pedicellate, completely investec in perisarc, oval, reaching a

diameter of 0,45 mm. Newly released medusa with two opposite marginal

tentacles. :

Adult medusa reaching 20 mm in depth, with conical or spherical apical

process, ‘mesenteries’ extending about halfway alung stomach, 12-24 marginal

tentacles, each with abaxial spur, 16 or more club-s*aped rudimentary tentacles.

Ocelli present.

Variation. The usual host for this species is Bullia annulata (Lamarck), but it

also occurs on Nassa speciosa Adams and N. anai+gica Sowerby and probably

on other gastropods as well. Vanh6ffen reports it (us Perigonimus vestitus) from

a crab, Halicarcinus sp.

The form of the colony varies according to the position on the host shell

and the amount of friction to which it is subject. On the under side hydranths

are small and the stems low (about 1 mm) and thus protected to some extent

in the grooves of the shell. In this position the co:ony seldom produces gono-

phores and sometimes only the hydrorhiza occurs. ‘Jn the upper surface of the

Shell and round the tip of the spire hydranths are !arger and stems taller and

often branched, reaching 5 mm. Here abundant medusa-buds are produced on

the stem, several to each, and rarely on the hydrorstiza.

Distribution. Cosmopolitan. Type locality: Bell Rock, Scotland.

Distribution in South Africa. False Bay to Algoa Bay in 3-82 m. Medusae from

Natal and Mocambique in 100-300 m. Hydranths- 34/18 (s), 34/23 (s), 34/25

(s), 33/25 (s), 33/26 (s). Medusae: 31/30 (d), 29/32 (d*. 25/36 (d). ;

SUBORDER THECATA

Diagnosis. Hydranth with a definite hydrotheca of definite shape; with one

whorl of filiform tentacles. Gonophores enclosed in gonothecae; in the form of

fixed sporosacs or free medusae. Medusa usually fattened or hemispherical;

with gonads on radial canals but sometimes contiguo:is with stomach; marginal

sense organs usually present, in the form of cordyli, ectodermal statocysts or,

occasionally, ocelli.

KEY TO FAMILIES

1. Hydrotheca with operculum ae $8 Es a ( a z 2

Hydrotheca without operculum .. ia Sa oe a ey Bs 3

2. Hydrotheca bilaterally symmetrical, usually with marginal teeth. Gastral endo-

derm differentiated .. ie $e x is ay SERTULARIIDAE p. 239

— Hydrotheca radially symmetrical, never with true marginal teeth. Gastral endo-

derm undifferentiated a3 ae 5 a: ae CAMPANULINIDAE p. 126

126 ANNALS OF HE SOUTH AFRICAN MUSEUM

3. Hydrotheca saucer- or basin-shaped, usually too small to contain contracted

hydranth Se .. HALECIIDAE p. 141

— Hydrotheca usually deep enough to contain contracted hydranth be ae 4

4. Hydrothecae always restricted to one side of stem or branches. Nematophores

present and with regular arrangement, usually 3 or 5S to each hydrotheca

PLUMULARIIDAE p32)

— Hydrothecae on two or more sides of stem or branches. Due if

present, seldom regularly arranged ars : B)

5. Hypostome trumpet-shaped. Hydrotheca always orentigalees, ‘ais campanu-

late and radially symmetrical. Margin toothed or untoothed CAMPANULARIIDAE p. 200

— Hypostome conical. Hydrotheca pedicellate or sessile, of varying shape, radially

or bilaterally symmetrical. Margin always untoothed .. aS 6

6. Hydrotheca with a.definite floor, always sessile and bilaterally Sytameteem

No nematothecae.. SYNTHECIIDAE p. 230

— Hydrotheca with no definite floor, “with ¢ or without diaphragm, diaphragm

when present always delicate. Hydrotheca pedicellate or sessile, bilaterally or

radially symmetrical. Nematothecae present or absent .. .. + LAFOEIDAE ‘p. 166

Family Campanulinidae

Diagnosis. Small thecate hydroids with stolonial colonies or sympodially

branched stems. Hydrotheca deep and usually cylindrical, with untoothed

margin, with a conical or roof-shaped operculum of converging segments which

may or may not be sharply demarcated from margin, with or without a dia-

phragm. Hydranth slender and extensile, completely retractable into hydrotheca,

with conical hypostome, with or without an intertentacular web. Nematophores

present or absent. Gonophores in the form of fixed sporosacs or free medusae.

Introduction. With the exception of a few authors in recent years polyp systema-

tists have grouped together all operculate hydroids other than the Sertulariidae

in the family Campanulinidae. These forms are mostly minute and inconspicuous

and show a certain uniformity in structure. Some of them produce fixed sporo-

sacs and others medusae, and in the latter the medusa is obviously the dominant

generation and its evolution has outpaced that of the polyp.

Medusa systematists, on the other hand, have independently grouped the

medusae among several different families, so that two completely different

systems of classification have arisen. Attempts to combine the two classifica-

tions into one have not so far been successful, due to the fact that the polyp

generation is still unknown for the majority of medusa species. Recent work on

life-histories has produced anomalous situations; for instance, two very similar

polyp species may produce medusae belonging to different families, e.g. Cuspi-

della produces medusae of the families Laodiceidae and Mitrocomidae; or polyps

of one medusa family may differ in structure, e.g. Eucheilota and Lovenella in the

Lovenellidae.

Rees (1939) felt that the medusa families should be used where possible,

transferring the polyps to them as the life-histories become known. However,

it is evident that the medusa families may also need revision. For instance, the

Lovenellidae are distinguished from the Phialellidae mainly by the presence of cirri

in the former, and Uchida (1964), in discussing the relationships of the polyp genus

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA Zi

Eugymnanthea, where some species produce Lovenellid medusae and another

a Phialellid medusa, remarked that ‘the cirri seem not to be very important’.

For a polyp systematist the only practical solution is to retain the family

Campanulinidae until such time that a better knowledge of both generations will

permit a critical reassessment of the whole group. A key to the currently used

medusa families based on the works of Kramp and Russell is, however, appended

to this section.

At the generic level, genera must be diagnosed primarily on the characters

of the type species, and where this is known for one generation only, the generic

name may have to be changed in the future. At present the medusa cannot be

deduced from the polyp or the polyp from the medusa.

Rees (1939) revised the genus Campanulina, retaining it solely for the type

species C. tenuis.

The polyp generation is generally minute and, unless specially reared, is

often encountered only in an epizootic or epiphytic habitat. The colony may be

stolonial, or it may produce upright stems which branch sympodially a few

times. Very rarely the stem is fascicled, when the sympodial character may be

largely obscured. The perisarc of the stem is usually firm, and annulated to a

varying degree.

The hydrotheca may be sessile, as in Lafoeina, but is more often pedicellate,

with a distinct, though sometimes very short, pedicel. The hydrotheca may

merge gradually into the pedicel, or be clearly demarcated from it by a well-

marked floor. In the aberrant genus Lineolaria the hydrothecae are adherent to

the algal substratum for almost the entire length.

The hydrotheca is typically cylindrical, but may be turbinate, deep bell-

shaped or deep ovate. It is always deeper than wide. Normally it is radially

symmetrical, but in Lineolaria it is bent up from the substratum and in Modeeria

the distal end is produced on two sides to support the operculum. There are

never true marginal teeth. A diaphragm occurs in some species and is always

extremely thin and delicate.

The OPERCULUM consists of a number of converging segments which close

over the retracted hydranth. There appear to be three main types:

(i) The segments are few (4-10) and distinct, seated in embayments of the thecal

margin and clearly demarcated from it. According to Kramp (1932) this

type of operculum is formed from the original roof of the growing hydrotheca,

e.g. Calicella, Lovenella and Tetrapoma, a small central part being discarded

in the first two. He includes these three genera in the polyp subfamily Cali-

cellinae.

(ii) There are only two pleated membranes which meet one another like the

roof of a gable and impart a bilateral symmetry to the distal part of the

hydrotheca, e.g. Modeeria.

(iii) The distal part of the hydrotheca wall is longitudinally creased or split to

form an irregular number of delicate valves which fold inwards in an untidy

manner to close the aperture. The valves are not clearly demarcated from the

hydrotheca, e.g. Eucheilota, Phialella, Aequorea, Lafoeina, Cuspidella, Oper-

cularella.

128 ANNALS OF THE SOUTH AFRICAN MUSEUM

TYPE 1 TYPE 2 TYPE 3

Fig. 42.

Campanulinidae: opercular types.

According to Kramp (1932) the operculum in Stegopoma (= Modeeria),

Lafoeina and Cuspidella is formed from the distal part of the hydrothecal wall,

the original roof being discarded. He included these three genera in the polyp

subfamily Cuspidellinae. He used a separate subfamily, Campanulininae, for

Opercularella, Campanulina, Oplorhiza and Egmundella, where the operculum

develops like that of the Calicellinae but the appearance is like that of the

Cuspidellinae.

The type of opercular development, though obviously important, cannot be

used to distinguish families as they stand at present, since, for instance, two

completely different types occur in the Lovenellidae (Lovenella and Eucheilota).

The hydranth is usually long and slender and very extensile. It often reaches

several times the length of the hydrotheca when fully extended and can be

completely withdrawn into the hydrotheca. The tentacles are equally extensile

and bear clusters or rings of nematocysts. In many species an intertentacular

web connects the bases of the tentacles and may contain accumulations of large

nematocysts (Fig. 43C). The endoderm of the hydranth is undifferentiated.

Nematophores are present in the genera Lafoeina, Oplorhiza, Egmundella

and in at least one species of Lineolaria. They are contained in nematothecae

which are round or tubular in shape.

Gonothecae may be borne directly from the hydrorhiza or from the stem.

Fixed sporosacs are diagnostic of the genera Calicella, Opercularella, Tetra-

poma and Lineolaria.

In conclusion it should be mentioned that there are certain species of the

medusa families Eutimidae and Eirenidae which produce polyps without

hydrothecae. Russell (1953) has assumed that the hydrothecae are reduced.

Brinckmann-Voss (1973) has proposed uniting these two families under the

name Eirenidae. Since no hydranths of this type are as yet known from South

Africa the problem can conveniently be postponed, and such polyps have not

been allowed for in the diagnosis of the Campanulinidae or in the keys.

KEY TO MEDUSA FAMILIES RELATED TO THE CAMPANULINIDAE

1. Producing fixed sporosacs .. ie ae is ane ty CALICELLIDAE

— Producing free medusae ed ae 3% 03 RA A os a so tee

oN ee See

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

Medusa with marginal cordyli re ae re he i .. LAODICEIDAE

Medusa without cordyli, with statocysts Pe vs eA

Statocysts open a site Be Se Be a fee MITROCOMIDAE

Statocysts closed

Medusa with distinct gastric Aetenels

Medysa without peduncle

Stomach very broad; many radial canals; with ereretels pores .. AEQUOREIDAE

EIRENIDAE (including EUTIMIDAE)

Stomach narrow; usually with 4 or 8 radial canals; with or without excretory pores

With excretory pores; 4-8 radial canals .. i: ue Ae PHIALUCIDAE

Without excretory pores; 4 radial canals .. A re i

Lateral or marginal cirri present .. bi af Be oF, LOVENELLIDAE

No cirri He ae Be es a, a: ae ae PHIALELLIDAE

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

Hydrotheca adherent to substratum x. : se & Lineolaria p.

Hydrotheca erect and free .

2. Operculum of two pleated membcaiies faeetines one nnothe! like the roof Bie a

gable : ee se Modeeria ps

Operculum pyramidal, of mr more than two valves

Operculum of 4 valves ;

Operculum of more than 4 valves: Be - be

Opercular valves sharply demarcated from By eo eee All .. [Tetrapoma]

Opercular valves not sharply demarcated from hydrothecal wall [Stegella]

Opercular valves seated in distinct EEG iRi ti of thecal margin and sharply

demarcated from it .

Opercular valves not sharply demarcated

Producing free medusae with lateral cirri ne: - 3 Lovenella p.

Producing fixed sporosacs ee a mae i Se Calicella p.

Nematophores present

Nematophores absent 4

Hydrotheca sessile and tubular; mieniaiolhecs Cone SaEOGhoTeS jaa

known, producing free medusae .. ; ve, ite [Lafoeina]

Hydrotheca pedicellate: nematotheca not tubular

Hydrotheca widest at distal end, tubular to top-shaped; Eenuuhoses: oe

known, producing free medusae .. .. Egmundella p.

Hydrotheea widest in middle, Harrowing at base and distal end; gonophores

unknown ... a Ne e hy [Oplorhiza]

Producing fixed sporosacs ee oe cot ee Opercularella p.

Producing free medusae

. Hydrotheca sessile, long and aenen Ss zs a (Cuspidela

Hydrotheca pedicellate

Hydranth without eaainealae Sis Nacdue Sino Se tai pores or

Githi «5. ve a ae me. Phialella p.

Hydranth with intertentacular +16) ; ae xt: ‘

. Medusa with excretory pores, without cirri as sm we Aequorea p.

Medusa without excretory pores, with lateral cirri a [Eucheilota]

Genus Aequorea Péron & Lesueur, 1809

129

Diagnosis. Colony stolonial or producing sparsely branched sympodial stems.

Hydrotheca minute, pedicellate and free, radially symmetrical, with an oper-

130 ANNALS OF THE SOUTH AFRICAN MUSEUM

culum of many converging segments not sharply demarcated from hydrothecal

wall. Hydranth with an intertentacular web. Nematophores absent. Gonophores

producing free medusae.

Medusa with broad stomach; with many unbranched radial canals; with

hollow marginal tentacles; with excretory pores; without cirri; with closed

statocysts; without ocelli. (Medusa family: Aequoreidae.)

Type species: Aequorea forskalea Péron & Lesueur, 1809.

One polyp species only from South Africa.

Aequorea africana Millard, 1966

Fig. 43A—-E

Aequorea africana Millard, 1966a: 461, fig. 8.

Diagnosis. Hydrorhiza creeping, giving rise to short stems which either bear a

single terminal hydrotheca or branch sympodially up to three times, each limb

terminating in a hydrotheca.

Stem reaching 2 mm, annulated or corrugated throughout, increasing in

diameter from base to distal end, not sharply demarcated externally from

hydrotheca.

Hydrotheca deep, tubular, very thin and membranous, with distal region

creased longitudinally to close the aperture, 0,3-0,6 mm in depth and 0,11-

0,18 mm in maximum diameter. Hydranth with 11-17 tentacles with a web

between the bases. Extended tentacles moniliform.

Gonotheca arising from hydrorhiza or stem on short, annulated pedicel;

pear-shaped, containing one medusa-bud.

Medusa structure unknown.

Variation. The length of the stem varies from 0,2 to 2,1 mm. Short stems are

closely and distinctly annulated, but the longer ones are closely annulated in the

basal part only and irregularly corrugated for the rest.

The base of the hydrotheca appears to be somewhat stouter than the rest,

and in dead or damaged specimens it is the only part which persists, forming a

saucer-shaped structure reminiscent of Halecium. Successive regeneration after

damage may result in tiers of saucer-shaped structures.

Remarks. This species shows strong resemblances to Eucheilota maculata as

described by Werner (1968), to Campomma hincksi as illustrated by Leloup

(1952), and to Campanulina paracuminata Rees, 1938, which is possibly the polyp

generation of Aequorea forskalea. The genus name is thus provisional pending

further knowledge of the life-history. Several Aequorea medusae have been

reported from South Africa (see p. 482).

Distribution. Endemic to South Africa.

Distribution in South Africa. Mossel Bay (type locality), Inhaca, in 18 m. 34/22

(s), 25/32

13]

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

age sn

fees

wean

Fig. 43.

Aequorea africana. A, hydrotheca and extended hydranth; B, hydrotheca and contracted

hydranth with gonophore; C, expanded hydranth showing intertentacular web; D, empty

stem surmounted by saucer-shaped structure which is all that remains of the hydrotheca;

E, gonotheca containing medusa-bud and arising from hydrorhiza.

Calicella oligista. F, hydrothecae redrawn from Stechow (1925a).

Egmundella amirantensis. G, hydrothecae and nematothecae.

Lineolaria gravierae sp. nov. H, surface view of colony. growing on weed.

Scale in mm/10.

132 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Calicella Hincks, 1861

Diagnosis. Colony stolonial. Hydrotheca pedicellate and free, deep and tubular.

Margin crenulated. Operculum of many converging segments, which do not

quite meet in the centre and which are clearly demarcated from the hydro-

thecal wall by a sharp and sometimes raised edge. No nematothecae. Hydranth

with no intertentacular web.

Gonophores in the form of fixed sporosacs.

Type species: Sertularia syringa Linnaeus, 1767.

One species from South Africa.

Calicella oligista Ritchie, 1910

Fig. 43F

Calycella oligista Ritchie, 19106: 813, pl. 76 (figs 3-4). Rees & Thursfield, 1965: 70.

Calicella oligista: Stechow, 1925a: 440, fig. 15.

Diagnosis. Hydrorhiza creeping, epizootic on other hydroids, giving rise to

solitary hydrothecae on short pedicels. Pedicel usually very short, always less

than half height of hydrotheca, smooth or irregularly twisted.

Hydrotheca deep-campanulate, smooth, delicate, minute, 0,12-0,14 mm

in depth and 0,05—0,07 mm in maximum diameter. Operculum of 12-14 con-

verging segments seated in wide bays of the margin. Diaphragm distinct, delicate.

Hydranth with 7-10 tentacles.

Gonotheca unknown.

Remarks. This species has not been reported since Stechow’s record. Its alloca-

tion to the genus Calicella is provisional pending the discovery of gonophores.

Distribution outside South Africa. Mergui Archipelago (type locality), Red Sea.

Distribution in South Africa. Plettenberg Bay, in 100 m. 34/23 (d)

Genus Egmundella Stechow, 1921

Diagnosis. Colony usually stolonial (but with branching fascicled stem in E.

fasciculata). Hydrotheca pedicellate, not sharply demarcated from pedicel,

turbinate or cylindrical, usually widest at level of opercular origin. Operculum of

triangular segments and (except in E. grandis) not sharply demarcated from

hydrotheca, and not seated in embayments of margin. Rarely a basal perisarcal

thickening. Nematotheca pedicellate, oval or spherical, borne on thecal pedicel

or on hydrorhiza.

Gonotheca, where known, cylindrical, arising from hydrorhiza, with an

operculum very like that of the hydrotheca, releasing free medusae.

Remarks. Gonophores are unknown in the type species of Egmundella, but have

been reported from EF. polynema Fraser. E. amirantensis definitely produces

medusae, but the adult medusa is unknown. See discussion by Vervoort (1966b:

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 133

109). Egmundella differs from the closely related Oplorhiza only in the shape of

the hydrotheca.

Type species: Egmundella gracilis Stechow, 1921.

One species only from South Africa.

Egmundella amirantensis Millard & Bouillon, 1973

Fig. 43G

Egmundella amirantensis Millard & Bouillon, 1973: 40, fig. 5SA—D

Diagnosis. Colony stolonial. Hydrothecal pedicel very short or absent. Hydro-

theca cylindrical, rounded at base, generally widest at level of opercular origin,

often slightly narrowed below this, 0,2-0,5 mm in depth and 0,08-0,11 mm in

marginal diameter. Operculum of about 11 fragile segments not clearly demar-

cated from one another or from thecal wall. Hydranth very extensile, with

9-13 tentacles and no intertentacular web.

Nematothecae arising from hydrorhiza, deep-oval, with slender pedicel,

containing a cluster of large, elongate nematocysts.

Gonotheca (not reported from South Africa) arising from hydrorhiza,

deep, irregular in outline, generally widening distally, containing one or two

medusa-buds, with faintly demarcated opercular segments.

Medusa with at least two marginal tentacles at release. Adult medusa

unknown.

Variation. The thecal pedicel is always very short, but may be quite absent so

that the hydrotheca is sessile. The hydrotheca is variable in length, and extra

long ones are possibly the result of regeneration though the perisarc is so delicate

that growth-lines are not visible. A perisarcal thickening may be visible in the

base. Occasionally a faint line may demarcate the opercular segments from the

hydrotheca.

Distribution outside South Africa. Seychelles: Amirante (type locality), Praslin

and Mahé.

Distribution in South Africa. Mocgambique, Inhaca to Santa Carolina. 26/32,

25/32, 21/35

Genus Lineolaria Hincks, 1861

Diagnosis. Colony stolonial and epizootic on weeds. Hydrotheca sessile or nearly

so, tubular or sac-shaped, adherent to weed for part or all its length, then bent

up. No diaphragm. Operculum present or absent, when present membranous

or of very delicate converging segments distinctly demarcated from hydrothecal

wall. Nematothecae present or absent.

Gonotheca adherent, where known containing fixed sporosacs.

Type species: Lineolaria spinulosa Hincks, 1861.

One species only from South Africa.

134 ANNALS OF THE SOUTH AFRICAN MUSEUM

Lineolaria gravierae sp. nov.

Fig. 43H

Lineolaria sp. Gravier, 1970a: 144, figs 11, 13A. Gravier, 1972: 8. Millard & Bouillon, 1974:

22 fis. 2D:

Holotype. An infertile colony growing on Cymodocea from Barreira Vermelha

on the west coast of Inhaca Island, Mocambique. Part of colony mounted on

slide in South African Museum (Cat. no. SAM-—-H1955) and part in Musée

Royal de l’Afrique Centrale, Bruxelles.

Diagnosis. Hydrorhiza generally running parallel to the long axis of the weed

substratum, in single, double or triple strands, each coated with a thin layer of

perisarc; giving rise to hydrothecae on both sides and to transverse strands

which usually form loops around the hydrothecae. Hydrothecae opposite,

alternate or irregular.

Hydrotheca tubular, adherent to weed for most of length, then bent

upwards, 0,4-0,6 mm in length and 0,16-0,2 mm in marginal diameter. Perisarc

thick near base, becoming thin distally. No pedicel, hydropore either open for

the full width of the hydrotheca or constricted to about one quarter of width.

Margin facing obliquely upwards, circular, untoothed, with an operculum of

many delicate converging segments. Hydranth with about 14 tentacles and a

conical hypostome.

Nematothecae borne on hydrorhiza on the transverse strands flanking the

hydrothecae, erect, not adherent, tubular, containing a group of large nemato-

cysts, reaching 0,2 mm in height.

Gonothecae (not reported from South Africa) adherent, obovate, smooth,

larger than hydrothecae, not bent up, with terminal aperture. Gonophores in

the form of fixed sporosacs. (From Gravier 1970a.)

Distribution outside South Africa. Madagascar.

Distribution in South Africa. Inhaca, Mogambique, only, on Cymodocea. 26/32

Genus Lovenella Hincks, 1868

Diagnosis. Colony stolonial or producing sparsely branched sympodial stems.

Hydrotheca minute, deep-campanulate, pedicellate and free, with a conical

operculum of about eight distinct converging segments seated in embayments

of the margin and sharply demarcated from the wall. Hydranth without inter-

tentacular web. Nematophores absent. Gonophores producing free medusae.

Medusa with small stomach; without peduncle; with four unbranched radial

canals; with hollow marginal tentacles; without excretory pores; with lateral

cirri; with an indefinite number (16 or more) of closed marginal vesicles; without

ocelli.

Remarks. The above diagnosis is based on the type species where the medusa

has been reared from the polyp (Russell 1953).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 135

Type species: Campanularia clausa Lovén, 1836.

One polyp species only from South Africa.

Lovenella chiquitita Millard, 1957

Fig. 44

Lovenella chiquitita Millard, 1957: 198, fig. 7. Millard, 19595: 250, fig. 3. Millard, 1966a: 464.

Diagnosis. Hydrorhiza creeping, often epizootic on other hydroids, giving rise

to short stems which either bear a single terminal hydrotheca or branch sym-

podially up to nine times, each limb terminating in a hydrotheca. Stem reaching

1,9 mm, annulated throughout, increasing in diameter from base to distal end,

not sharply demarcated externally from hydrotheca.

Hydrotheca deep-campanulate, smooth, minute, 0,13-0,3 mm in depth and

0,09-0,16 mm in marginal diameter. Margin with 8-10 wide and shallow bays.

Operculum of 8-10 converging segments with a gap between their central points.

Diaphragm delicate. Hydranth with over 12 tentacles.

Gonotheca arising from hydrorhiza on short, annulated pedicel; smooth,

elongated, tapering below, truncated above, containing two medusa-buds.

Medusa at liberation with eight unbranched, marginal tentacles, without

cirri, with eight closed adradial marginal vesicles each containing two concre-

tions, with a short stomach and a simple, quadrangular mouth; 0,3 mm in depth

and 0,4 mm in diameter. (Medusa family: Phialellidae.)

Variation. The proportions of the hydrotheca are variable; in some the diameter

is almost equal to the depth and in others the depth is almost three times the

diameter. The perisarc of the hydrotheca is usually very delicate, but sometimes

thicker and in this case there may be an annular thickening just below the

diaphragm.

Observations on living material. Living hydranths are long, slender and very

extensile, the tentacles being held alternately elevated and depressed. Gono-

phores have released medusae in the laboratory, but the latter have not been

reared to maturity. The young medusae have four of the eight marginal tentacles

slightly longer than the others.

Colour: hydranths transparent; medusae transparent, with brown patches

on tentacle-bases and in stomach.

Remarks. The polyp generation of this species closely resembles that of the

type species of Lovenella, hence its inclusion in this genus. The newly released

medusa, however, differs from that of Lovenel/a in the absence of cirri.

Distribution. Endemic to South Africa. Type locality: False Bay.

Distribution in South Africa. Liideritz Bay to False Bay, littoral to 40 m. 26/15

(s), 33/18 (h, 1); 34/18 (h, 1, s)

136 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 44.

Lovenella chiquitita. A, branching stem and gonotheca; B-—D, hydrothecae, D with partly

extended hydranth; E, young medusa escaping from gonotheca; F, newly liberated

medusa, preserved and somewhat contracted.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 137

Genus Modeeria Forbes, 1846

Syn. Tiaranna Hartlaub, 1914.

Diagnosis. Colony stolonial. Hydrotheca pedicellate, deep and tubular, with

margin produced on two sides. Operculum of two longitudinally pleated

membranes seated in the embayments of the margin and meeting one another

like a gable. No diaphragm. No nematothecae. No intertentacular web. Gono-

theca similar to hydrotheca. Producing free medusae.

Medusa with thick jelly; with large quadrangular stomach attached to

subumbrella along margins of four cruciform perradial furrows; mouth with

four well-developed folded lips; with four simple radial canals; gonads in

sinuous folds along sides of perradial furrows; with numerous hollow marginal

tentacles with conical basal bulbs; with cordyli; without ocelli; without

statocysts. (Medusa family: Laodiceidae.)

Type species: Dianaea rotunda Quoy & Gaimard, 1827.

Remarks. Edwards (1973) traced the development of the well-known Stegopoma

fastigiatum (Alder) and linked it to the medusa Modeeria rotunda (Quoy &

Gaimard). This is the only member of the genus Modeeria in which the hydranth

is known, and on it is based the diagnosis given above. Further knowledge of the

life-history of other species of Stegopoma (including the type species, S. plicitale)

is required in order to decide whether they also should be included in Modeeria

or whether the genus Stegopoma should be retained. Edwards transferred the

genus Modeeria from the Tiarannidae to the Laodiceidae.

One species only from South Africa.

Modeeria rotunda (Quoy & Gaimard, 1827)

Fig. 45A

Dianaea rotunda Quoy & Gaimard, 1827: 181, pl. 6A (figs 1-2).

Campanularia fastigiata Alder, 1860: 73, pl. 5 (fig. 1).

Tiaranna rotunda: Russell, 1953: 219, figs 117-119.

Stegopoma fastigiata: Millard, 1958: 175.

Modeeria rotunda: Edwards, 1973: 573, figs 1-3.

Diagnosis. Colony epizootic on other hydroids. Hydrorhiza creeping, giving

rise to solitary, pedicellate hydrothecae and gonothecae.

Hydrotheca 0,4-1,8 mm in length and 0,2-0,4 mm in maximum diameter,

not sharply demarcated from pedicel, which is smooth, and 0,1—1,2 times length

of hydrotheca. Hydranth with about 13 tentacles. Operculum as for genus.

Gonotheca similar to hydrotheca but wider, with very short, smooth

pedicel, containing a series of medusa-buds.

Medusa (not recorded from South Africa) at liberation deep and some-

what conical, with umbilical canal, four oral lips, four perradial marginal bulbs

with well-developed tentacles, four interradial and four or eight adradial

marginal bulbs which may bear rudimentary tentacles, about 2 mm in diameter

138 ANNALS OF THE SOUTH AFRICAN MUSEUM

and 1,5 mm in height. Adult medusa as for genus, reaching 22 mm in diameter,

with up to 28 marginal tentacles.

Variation. The size of the hydrotheca and length of its pedicel are notoriously

variable in this species.

Distribution. Cosmopolitan. Type locality: Straits of Gibraltar (medusa).

Distribution in South Africa. East coast, from Natal to Mocgambique, in 70

to 347 m. 30/31 (d), 29/31 (s, d), 26/33 (d), 24/35 (d)

Genus Opercularella Hincks, 1868

Diagnosis. Colony stolonial or sympodially branched. Hydrotheca pedicellate

and free, deep and tubular. Operculum of many converging segments, which

do not quite meet in the centre, and which are not sharply demarcated from the

hydrothecal wall. No nematothecae. Hydranth with no intertentacular web, or

if present, not well developed.

Gonophores in the form of fixed sporosacs.

Remarks. Rees (1939) advocated the retention of the genus Opercularella for

species previously assigned to Campanulina and*which produce fixed sporosacs,

and also (provisionally) those species in which the gonosome is unknown. The

only South African species falls in the latter category.

Type species: Campanularia lacerata Johnston, 1847.

Opercularella sp.

Fig. 45C-D

?Opercularella spec. no. 2: Vervoort, 1966b: 108, figs 8, 12b.

Diagnosis. Colony erect and branching sympodially, reaching 22 mm. Stem

fascicled in lower regions, straight, giving rise to branches and more-or-less

alternate hydrothecae, with occasional nodes immediately above origins of

hydrothecae. Branches similar to stem.

Hydrotheca pedicellate. Pedicel shorter than hydrotheca and not sharply

demarcated from it, more-or-less distinctly ringed or indistinctly wrinkled.

Hydrotheca tumbler-shaped, sometimes slightly swollen near base, with flaring

margin, 0,3-0,4 mm in depth from diaphragm and 0,16-0,19 mm in maximum

diameter. Operculum formed from distal part of hydrotheca which folds

longitudinally along 10-12 longitudinal striae. A thin diaphragm present.

Gonotheca unknown.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only record: off Durban in 430 m.

29/31 (d)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 139

~ “5

Fig. 45.

Modeeria rotunda. A, hydrothecae from different colonies, and gonotheca on extreme right.

Phialella turrita. B, hydrothecae and gonotheca, redrawn from VanhOffen (1910, as Campanulina

turrita).

Opercularella sp. C and D, redrawn from Vervoort (19665).

Scale: D in mm, the rest in mm/10.

140 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Phialella Browne, 1902

Diagnosis. Colony stolonial or producing sympodially branched stems. Hydro-

theca minute, deep and conical, pedicellate and free, with an operculum of

many acute converging segments not sharply demarcated from hydrothecal wall.

Hydranth without intertentacular web. Nematophores absent. Gonophores

producing free medusae.

Medusa with small stomach, without peduncle, with four unbranched

radial canals, without excretory pores, with many hollow marginal tentacles,

without cirri, with eight closed statocysts, without ocelli. Newly hatched

medusa with four marginal tentacles. (Medusa family: Phialellidae.)

Remarks. The polyp generation is not known in the type species. The above

diagnosis is based on the polyp of P. quadrata (Forbes). This species was reported

by Allman (1864) to have a very shallow intertentacular web, but Russell (1953)

says this is not confirmed, and Huvé (1952) illustrates the tentacle bases without

a web.

Type species: Phialella falklandica Browne, 1902.

One polyp species only from South Africa.

Phialella turrita (Hincks, 1868)

Fig. 45B

Campanulina turrita Hincks, 1868: 190, pl. 36 (fig. 2). VanhGffen, 1910: 309, fig. 29.

Hypsorophus quadratus, forme turritus: Huvé, 1952: 39, figs 3-4.

Diagnosis. Stem bearing a single terminal hydrotheca or several hydrothecae

in a sympodial manner, two or three at a time; occasionally branching

sympodially; distinctly annulated throughout.

Hydrotheca deep, widening gradually upwards, 0,2-0,4 mm in depth and

0,10 mm in diameter. Operculum of short converging segments, about 4 depth

of hydrotheca. No diaphragm.

Gonotheca arising from hydrorhiza or stem, pear-shaped, containing

one medusa-bud.

Remarks. Vanh6ffen identified his material from South Africa as Campanulina

turrita Hincks. This species has been ascribed to Aequorea by Rees (1939) and to

Phialella (Hypsorophus) quadrata by Huvé (1952). Huvé’s identification was

queried by Rees & Thursfield (1965).

Vanh6offen’s material strongly resembles ‘Campanulina’ repens, the polyp

generation of Phialella quadrata. 1 have therefore included the species in the

genus Phialella, but have retained the specific name turrita pending further

information on the life-history.

Distribution outside South Africa. Great Britain (type locality), Mediterranean,

Greenland, Denmark, Falklands, New Zealand. (Phialella quadrata is known

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 141

from the Atlantic, Pacific and Indian Oceans, though it has not as yet been

reported from South Africa.)

Distribution in South Africa. Simonstown in False Bay. 34/18 (s)

Family Haleciidae

Diagnosis. Thecate hydroids with shallow, saucer- or basin-shaped hydrothecae.

Hydrotheca radially symmetrical, without operculum, with untoothed margin,

usually with diaphragm. Hydranth very large and usually not completely

retractable into hydrotheca, with conical hypostome and one circle of filiform

tentacles, endoderm differentiated into proximal digestive part and distal non-

digestive part. Nematophores present or absent. Gonophores in the form of

fixed sporosacs, or, rarely, freed as medusae.

Introduction. The majority of the Haleciidae have upright branching stems with

sympodial growth. The stems and their branches are divided into internodes,

each typically bearing a hydrotheca on an apophysis near its distal end. The

apophyses occur alternately on the right and on the left, so that the hydrothecae

form two longitudinal rows. The stem may be fascicled or unfascicled, but the

final branches are always unfascicled.

In the genera Hydranthea Hincks (1868) and Campalecium Torrey (1902),

which do not occur in South Africa, and in Hydrodendron cornucopia, which

does, the colony is stolonial. A stolonial form may also occur in normally erect

species.

The hydranths are always large. In Halecium they cannot be contained in

the shallow hydrothecae; in Hydrodendron, where the hydrothecae are a little

deeper, they can be almost or entirely contained. The base of the hydrotheca

generally contains a diaphragm on which the hydranth rests. The hydranth

is fastened to the wall of the hydrotheca above the level of the diaphragm by

coenosarcal strands, whose position is normally marked in the empty hydrotheca

by a ring of REFRINGENT NODULES. The gastral cavity of the living hydranth is

usually (and possibly always) divided by a transverse constriction into twc

distinct regions, the oral and the aboral or digestive. In some species of Hydro-

dendron, Hydranthea and Campalecium the bases of the tentacles may be attached

to one another by an intertentacular web. The web is absent in Halecium.

The hydrotheca may be sessile, with its base resting directly on the apophysis

and its adcauline wall usually adnate to the stem, or pedicellate. The pedicel is

normally of the same diameter as the hydrotheca and is not externally

demarcated from it. Regeneration is very common, resulting in tiers of hydro-

thecae arising one within the other. The secondary hydrothecae may differ

from the primary one in the presence of a pedicel; for instance in Halecium

beanii the primary hydrotheca is sessile and the secondary hydrothecae have

pedicels of a characteristic shape. In the literature the hydrotheca plus its pedicel

are often referred to as a HYDROPHORE. In the diagnoses of species which follow,

142 ANNALS OF THE SOUTH AFRICAN MUSEUM

adcauline side refringent nodules

abcauline side

A. ~ diaphragm

‘___pseudodiaphragm

secondary hydrotheca

LP primary hydrotheca

hydrophore

pedicel

apophysis

internode

Fig. 46.

Haleciidae: parts of the skeleton. On the left a sessile hydrotheca with straight walls, on the

right a pedicellate and regenerated hydrotheca with everted wails.

the depth of the hydrotheca is measured from the diaphragm to the margin.

In some species a thickened shelf of perisarc may occur below the base of the

hydrotheca in the pedicel and is usually better developed on one side than the

other. This is termed a PSEUDODIAPHRAGM, e.g. Halecium delicatulum, Halecium

?muricatum.

Nematophores are present in the genus Hydrodendron. The nematothecae

are one-chambered, minute, cup-like or tubular, often without any regular

arrangement.

In the genus Hydranthea the gonophores are naked. Generally, however,

they are enclosed in gonothecae, which are generally dioecious. In some species

of Halecium the female gonophores are very obviously modified hydranths.

In H. beanii and H. dichotomum two well-developed hydranths protrude through

the opening of the gonotheca. In H. delicatulum a hydranth is recognizable,

through completely contained within the gonotheca and without mouth and

tentacles. In other species, e.g. H. tenellum, and in the males of all species the

resemblance to a hydranth is lost.

In snost genera the gonophores take the form of fixed sporosacs. In Cam-

palecium, however, the gonophores release free medusae, and in the only species

of the genus, C. microtheca (= C. medusiferum), the medusa was shown by

Brinckmann (1959) to be Eucheilota (Lovenella) cirrata, a member of the Cam-

panulinidae. This suggests a relationship between the Campanulinidae and the

Haleciidae and it is possible that the latter arose from the former by the loss

of the operculum and distal part of the hydrotheca in the polyp generation.

This is supported by the fact that in certain campanulinids, e.g. Eucheilota

maculata, Eutonina indicans and Aequorea africana (Werner 1968; Millard 1966a)

the distal part of the hydrotheca may be sloughed off in older colonies leaving a

shallow, basin-shaped structure similar to the hydrotheca of the Haleciidae

and complete with diaphragm and refringent nodules. The relationship between

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 143

these two families is further supported by the presence of an intertentacular web

in certain members of both and by some similarities in the cnidome.

In some of the species of Hydrodendron with deeper hydrotheca and with

nematothecae, e.g. H. gracilis and H. cornucopia, the structure of the colony

approaches very closely that in some Plumulariidae and Lafoeidae and it may

be difficult to draw a dividing line between these families.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Nematophores present Be a a - ae Hydrodendron jor. Shes

— Nematophores absent a ie A 42 P. ae ee a 2

2. Colony stolonial Sh bye sy a oe a Re ae, - 3

— Colony with erect stem es ae ae we = : oe Ws 4

3. Producing medusae as es es aN M [Campalecium]

— Producing fixed sporosacs .. f ae Le [Hydranthea]

4. Hydrothecae borne on stem and BR ache es i We Halecium p. 143

— Hydrothecae borne on branches only “a ae i [Hemitheca]

Genus Halecium Oken, 1815

Diagnosis. Colonies generally upright with sympodial growth. Stem (and

branches when present) bearing two rows of alternate hydrothecae, divided

into internodes, each internode with a hydrotheca-bearing apophysis near

distal end. Hydrotheca sessile or pedicellate, shallow, basin- or saucer-shaped,

with delicate diaphragm and generally a ring of refringent nodules above it.

Regeneration common, resulting in tiers of secondary hydrothecae growing

from within the primary. Hydranth large, without intertentacular web. Nema-

tophores absent. Gonophores in the form of fixed sporosacs contained in

gonothecae. Gonothecae solitary, not aggregated, male and female usually

dissimilar and on separate colonies.

Type species: Sertularia halecina Linnaeus, 1758.

KEY TO SPECIES

. Hydrothecal wall straight, usually widening to et but never ev’ sted aS ee

Hydrothecal wall asd ae ee 5 ae ae had oie ae Beal,

. Hydrotheca deep (dept o nag tn darieten : un .. H. dyssymetrum

Hydrotheca shallow een ‘less than + marginal diameter) ie ane cas 3

. Female gonotheca with lateral opening containing two aes ae a Serene

Female gonotheca with terminal opening . ee ue 5 aa

. Hydrotheca not widening to margin. Paanetls Beecinely with infer: feene aperture

on concave side bs H. sessile

Hydrotheca widening to margin. Female gonotheca with distal- facing aperture on

concave side .. 3 >

. Stem fascicled, ste any riche with aomnecie offset allennniely to ohe aaa left,

not narrowed or corrugated at nodes : H. beaniti

Stem unfascicled, geniculate and bent alternately to left and right below each node.

with hydrothecae not offset, constricted at nodes and immediately above them

H. lankesteri

144 ANNALS OF THE SOUTH AFRICAN MUSEUM

6. Female gonotheca slender, usually curved, containing several eggs in one row

H. halecinum

— Female gonotheca compressed, oval in side view, containing one egg H. inhacae

7. Stem unfascicled, short (under 7 mm). Hydrotheca with wall strongly everted through-

out, small (diameter at margin under 0,18 mm). No pseudodiaphragm. Female

gonotheca smooth, compressed-ovoid, with terminal aperture and no hydranths

H, tenellum

— Stem fascicled ae be SP i

8. Hydrotheca deep (depth over 3 Ddismeteny Bara, Rydothecs pedicellate, pedicel

separated from apophysis by node Hydrothecal wall strongly everted in marginal

region. Usually two pseudodiaphragmata. (Female gonotheca ridged and spiny)

A. 2muricatum

Hydrotheca shallow (depth less than 4+ diameter) Pe a - esa)

9. Primary hydrotheca usually sessile. Hydrothecal wall usually everted only at margin.

No pseudodiaphragm. Female gonotheca annulated, with lateral opening and two

hydranths . H. dichotomum

— Primary hydrotheca ‘pedicellate, pedicel ‘not separated from “apophysis by node.

Hydrothecal wall strongly everted throughout. Usually one pseudodiaphragm.

Female gonotheca smooth, flat and eared, containing one reduced hydranth without

tentacles Ne ke te a ie oe: ae, he Hi. delicatulum

Halecium beanii (Johnston, 1838)

Fig. 47A-E

Thoa beanii Johnston, 1838: 120, pl. 7 (figs 1-2).

Halecium beanii: Hincks, 1868: 224, pl. 43 (fig. 2). Ralph, 1958: 332, fig. 10a—b, e-k. Vervoort,

19666: 103, fig. 3. Millard, 1966a: 464, fig. 9A-F. Vervoort, 1972: 30, figs 6-7.

Diagnosis. Colonies shrubby and stiff in appearance, 10-70 mm in height. Stem

fascicled, branching irregularly or in a roughly alternate manner, segmented,

usually straight, each internode giving rise to a hydrotheca from an apophysis

near the distal end, the two rows of hydrothecae in one plane or shifted onto

the anterior surface of the stem. No annulation of internodes. Branches arising

from below or within hydrothecae, often rebranching many times.

Primary hydrothecae sessile. Secondary hydrothecae pedicellate. Pedicel

typically with a constriction immediately above origin, gibbous above this, then

narrowed and then widening gradually to distal end. Hydrotheca shallow, with

straight sides, widening to margin, which is not everted, 0,03-0,05 mm in depth

and 0,13-0,17 mm in marginal diameter. Diaphragm delicate, with a ring of

refringent nodules immediately above it.

Male gonotheca spindle-shaped, smooth, without hydranths. Female

gonotheca ‘mitten-shaped’, elongated and curved, with distal-facing aperture in

centre of concave side, smooth, with two fully-formed hydranths emerging from

aperture, containing a single row of large eggs.

Variation. The stem is occasionally slightly geniculate and the nodes are very

variable in length.

The secondary hydrothecae normally bend away from the stem, due to the

asymmetrical development of that part of the pedicel below its constriction,

which is longer on the adcauline side. That part above the constriction may be

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 145

symmetrical or asymmetrical, the latter condition due to unequal development

of the bulge near the base or to curvature of the whole pedicel. Likewise, the

hydrothecal margin may be perpendicular to the axis of the pedicel, though it is

more often oblique and tilted towards the adcauline side.

The female gonothecae sometimes tend to be S-shaped, with the proximal

end convex on the adcauline side.

Remarks. There is no certain way of distinguishing H. beanii from H. halecinum

in the absence of female gonothecae. Both species occur in South Africa. In the

distribution which follows, therefore, all records without female gonothecae,

including those from the literature, have been disregarded. The species is cer-

tainly far more common than is indicated, and sterile material, probably of

this species, has been found as far north as Inhambane on the east coast (23/35).

Distribution. Cosmopolitan. Type locality: near Scarborough, England.

Distribution in South Africa. From Lideritz Bay, South West Africa, on the

west coast to the northern boundary of the Cape on the east coast, littoral to

157 m. 26/15 (s), 33/17 (s, d), 33/18 (, s), 34/18 (s), 34/19, 34/22 (s), 33/25 (s),

34/25 (Ss); 33/26 (s), 33/27 (s), 32/28 (s), 31/29

Halecium delicatulum Coughtrey, 1876

Fig. 47F-L

Halecium delicatulum Coughtrey, 1876: 26, pl. 3 (figs 4-5). Ralph, 1958: 334, fig. lle, h—-n,

12 a—p. Millard, 1966a: 464, fig. 10L. Vervoort, 1972: 27, figs 4-5.

Halecium flexile Allman, 1888: 11, pl. 5 (fig. 2).

Halecium gracile Bale, 1888: 759, pl. 14 (figs 1-3).

Halecium parvulum Bale, 1888: 760, pl. 14 (figs 4-5). Millard, 1957: 189, fig. 4A. Vervoort,

1959: 227, fig. 7.

Halecium parvulum, var. magnum Millard, 1957: 190, fig. 4B—O.

Diagnosis. Colony stiff and bushy, reaching 190 mm in height. Stem usually

fascicled, profusely and irregularly branched, segmented, each internode giving

rise to a hydrotheca from an apophysis near the distal end, the two rows of

hydrothecae usually in one plane. Branches arising from hydrothecal pedicels,

smaller ones flexuous and graceful.

Primary hydrotheca pedicellate; pedicel variable in length, tubular, con-

tinuous with stem apophysis and not demarcated from it by a node. Secondary

hydrotheca pedicellate; pedicel tubular, often constricted or annulated at base.

Primary and secondary pedicels commonly with a pseudodiaphragm which is

better developed on adcauline side. Hydrotheca shallow, with wall strongly

everted, more so on adcauline side, 0,03-0,08 mm in depth and 0,13-0,4 mm

in marginal diameter. Diaphragm delicate, with a ring of refringent nodules

immediately above it. Margin usually perpendicular to axis of pedicel.

Gonothecae arising from stem or hydrorhiza. Male gonotheca compressed,

elongate-oval in side view, smooth, without hydranths; when immature flat-

tened and disc-shaped. Female gonotheca large, compressed, smooth, elongate-

46 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 47.

Halecium beanii. A, stem with female gonothecae: B and C, regenerated hydrothecae; D, male

gonophore; E, female gonophore.

Halecium delicatulum. F and G, parts of stem from small form (F) and large form (G); H, male

gonophore; J—L, female gonophores, the first two showing hydranths, the third containing

planulae.

Scale: H-L in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 147

oval in side view with two distal ‘ears’ and between them a small terminal

aperture at the base of an inverted collar; when immature flattened-oval with

rounded distal end. Female gonotheca containing a single reduced hydranth

without mouth or tentacles and bearing eggs, three or four of which mature into

planulae.

Variation. This species is capable of great variation in size and the following

forms can be distinguished:

(i) Small form. Marginal diameter of hydrotheca under 0,25 mm. Mature female

gonotheca under 1,5 mm in length.

(ii) Large form (var. magna Millard 1957). Marginal diameter of hydrotheca

over 0,25 mm. Mature female gonotheca over 1,5 mm in length.

The growth-form also varies, from luxuriant heavily-fascicled colonies to

small unfascicled ones. Sometimes interconnection of the superficial tubes of

the stems results in a tangled formless mass. In all cases, however, the smaller

branches have a more delicate and flexuous appearance than, for instance, in

H. beanii. The stem may be straight or zigzag, the internodes long or short,

and there is usually an indication of annulation or twisting in the neighbourhood

of the nodes. Occasionally athecate internodes may occur.

The pedicels of the hydrothecae may be straight or curved, and the greater

development of the pseudodiaphragm and curvature of the hydrothecal wall

on the adcauline side may impose a bilateral symmetry.

Male and female gonothecae change in shape during development, and

abnormalities sometimes occur, such as the presence of two apertures and two

reduced hydranths in the female.

Distribution outside South Africa. Circumglobal in tropics and southern oceans,

extending northwards to Japan in the Pacific and Morocco in the Atlantic,

and southwards to the Antarctic. Type locality: Dunedin (New Zealand).

Distribution in South Africa. From the west coast of the Cape Province to

Mocgambique, very common in False Bay and on the Agulhas Bank, littoral to

219 m. 30/15 (d), 32/18 (s), 33/17 (s), 33/18 Cl, s), 34/18 (I, s, d), 34/20 (s), 34/21

(d), 35/21 (d), 34/22 (s), 35/22 (d), 34/23 (d), 33/25 (s), 34/25 (s), 33/26 (s),

33/27 (s), 33/28 (s), 32/28 (s), 31/29 (s), 29/31 (d), 26/35 (d), 24/34 (s), 24/35 (s)

Halecium dichotomum Allman, 1888

Fig. 48A—G

Halecium dichotomum Allman, 1888: 13, pl. 6. Millard, 1957: 188. Millard, 1966a: 466, fig.

10A-K.

Diagnosis. Colonies varying from tall and robust to low and scrubby. Stem

fascicled, fairly stiff, though unable to support itself out of fluid, segmented,

typically branching repeatedly in a dichotomous manner in which two, or

occasionally three, equally developed limbs arise at the same level from curved

148 ANNALS OF THE SOUTH AFRICAN MUSEUM

apophyses near the distal ends of the internodes. Hydrothecae terminating

internodes. Smaller branches flexuous and usually geniculate.

Primary hydrothecae normally sessile. Secondary hydrothecae pedicellate.

Pedicel more or less symmetrical, usually annulated in basal region and then

widening to distal end. Hydrotheca shallow and wide, with wall usually straight

and widening towards margin for most of its height, then sharply everted,

0,03-0,05 mm in depth and 0,18-0,3 mm in marginal diameter. Margin usually

perpendicular to axis of internode or pedicel. Diaphragm delicate, with a ring

of refringent nodules immediately above it.

Male gonotheca slender, tapering to distal aperture, sometimes curved,

annulated for all or most of length. Female gonotheca mitten-shaped, with

rounded distal end and distal-facing aperture on one side, closely annulated,

with two fully-formed hydranths emerging from aperture, containing two or

three large eggs.

Variation. The hydrorhiza is smooth, annulated or roughly corrugated, and in

epizootic colonies is capable of putting out rootlike projections to anchor the

colony.

The growth-form and general appearance of the colony is very variable

and all grades between the following extremes may occur:

(i) Large upright colonies reaching 110-120 mm in height, with strongly fas-

cicled stems and branching mainly in one plane. Main stem more or less

straight and dichotomy not obvious, due to the fact that one limb is enveloped

by the peripheral tubes and contributes to the axis of the stem, while the

other is short and forms a branch. Larger stems and branches stiff in appear-

ance and up to 2 mm thick, though unable to support themselves out of

fluid. Smaller branches graceful and flexuous. Stem and branches with long

internodes with no annulation other than a shallow constriction near base.

Secondary hydrothecae scarce.

(ii) Low, scrubby colonies, often epizootic, reaching a height of 10-20 mm.

Stem usually weakly fascicled and strongly geniculate. Branching profuse

and in all planes, and stolonization common resulting in a tangled mat which

may cover large areas of the substratum and is very easily recognized. Dicho-

tomy very obvious. Internodes of stem and branches shorter and more annu-

lated. Secondary hydrothecae abundant and pedicels often closely annulated

in basal regions.

The shape of the hydrotheca is also variable. Typically the wall is straight

until close to the margin where it suddenly flares out, but the flaring may be

much more extensive resembling that in H. delicatulum, or the flared-out

portion may be largely worn off in old colonies. Variations in the shape of the

pedicels of secondary hydrothecae and in the angle of the margin may also occur.

Primary hydrothecae often have quite long pedicels. The perisarc is typically

thin and a pseudodiaphragm only rarely occurs.

Solitary, pedicellate hydrothecae may also arise separately from the

hydrorhiza.

Distribution. Endemic to South Africa. Type locality: Simon’s Bay, Cape.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 149

()

x Cexgl K

ial “

Fig. 48.

Halecium dichotomum. A-C, regenerated hydrothecae; D, part of stem showing unilateral

branching; E, part of stem showing dichotomous branching; F, female gonophore;

G, male gonophore.

Halecium dyssymetrum. H, part of stem; J, hydrotheca.

Halecium sessile. K—M, parts of stem, redrawn from Vervoort (19668).

Scale in mm/10.

150 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. All round the coast from Liideritz Bay in South

West Africa to Mocambique, in 11-200 m. 26/15, 32/18 (s), 33/17 (s), 34/18 (s),

34/20 (s), 34/21, 35/21 (d), 34/22 (s), 35/22 (d), 34/23 (s, d), 34/24 (d), 33/25 (s),

34/25 (s, d), 33/26 (s), 33/27 (s), 32/28 (s), 33/28 (Ss), 29/31 (s, d), 24/34 (s)

Halecium dyssymetrum Billard, 1929

Fig. 48H, J

Halecium dyssymetrum Billard, 1929: 307, fig. 1C. Leloup, 1935: 8, fig. 1.

Diagnosis. Stem under 10 mm in height, unfascicled, unbranched, segmented,

slightly geniculate, each internode giving rise to a hydrotheca from an apophysis

near the distal end, the two rows of hydrothecae in one plane. No annulation of

internodes.

Primary hydrothecae sessile. Secondary hydrothecae with assymetrical

pedicels widening distally and usually bent outwards. Hydrotheca deep, widening

to margin, which is not everted, 0,13-0,17 mm in depth and 0,2-0,3 mm in

marginal diameter. Diaphragm very thick and pronounced, more so on adcau-

line side. Base of hydranth attached above diaphragm and attachment marked

by a ring of refringent nodules, each of the latter shaped like an Indian wigwam.

Gonothecae unknown.

Distribution outside South Africa. Dutch East Indies (type locality), West Indies.

Distribution in South Africa. One record only, from off Mogambique in 55 m.

24/34 (s)

Halecium halecinum (Linnaeus, 1758)

Fig. 49A-E

Sertularia halecina Linnaeus, 1758: 809.

Halecium halecinum: Hincks, 1868: 221, pl. 42. Broch, 1909: 144, figs 4-5. Vervoort, 1946a:

158, figs 63-64. Millard, 1966a: 468, fig. 9G—-L.

Diagnosis. Stem under 10 mm in height (but see under ‘Variation’ below),

fascicled or unfascicled, branched or unbranched, segmented, straight or slightly

geniculate, each internode giving rise to a hydrotheca from an apophysis near

the distal end, the two rows of hydrothecae in one plane or shifted on to the

anterior surface of the stem. No annulation of internodes.

Primary hydrothecae sessile. Secondary hydrothecae pedicellate. Pedicel

typically with a constriction immediately above origin, gibbous above this

and then widening gradually to distal end. Hydrotheca shallow, with straight

sides, widening to margin, which is not everted, 0,03-0,05 mm in depth and

0,i2-0,15 mm in marginal diameter. Diaphragm delicate, with a ring of

refringent nodules immediately above it.

Male gonothecae (not recorded from South Africa) spindle-shaped,

smooth, without hydranths. Female gonotheca elongate, usually curved,

widening slightly to distal end, which is truncated and bears a terminal aperture

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 151

on the adcauline side, smooth, with two fully-formed hydranths emerging from

aperture, containing a single row of 2-4 large eggs or planulae.

Variation. The only certain records from South Africa are stunted colonies, but

tall, rigid and pinnately branched stems occur in the North Atlantic reaching

100-200 mm or more in height. The terminal branches are said to be stiffer

than in H. beanii and the whole colony much more regularly branched and

less ’bushy’.

The hydrothecae are indistinguishable from those of H. beanii, but second-

ary hydrothecae and their pedicels are always asymmetrical, due either to

unequal development of the proximal part of the pedicel, or to curvature of the

whole pedicel away from the stem, The margin of the secondary hydrotheca is

usually oblique to the axis (tilted towards the adcauline side) and seldom

perpendicular as is said to be the rule for the species.

Remarks. As in the case of H. beanii this species is probably more abundant

than is indicated by the records, since samples without female gonothecae have

been disregarded, including that of Ritchie (19075) from South Africa, who had

only male gonothecae which might easily be confused with H. beanii.

Distribution outside South Africa. Certainly from the North Sea, North Atlantic

and Arctic, but probably much more widespread. Type locality: U.K.

Distribution in South Africa. Agulhas Bank in 27 m and Inhaca, 10-15 m.

33/27 (s), 26/32 (s)

Halecium inhacae Millard, 1958

Fig. 49F-H

Halecium inhacae Millard, 1958: 168, fig. 1.

Diagnosis. Colony small and inconspicuous, reaching 4 mm in height. Hydro-

rhiza with internal thickenings of perisarc. Stem unfascicled, usually unbranched,

with segmentation inconspicuous or absent, slightly geniculate. Hydrothecae

arising from short apophyses of stem, one to an internode where these are evi-

dent, the two rows in one plane. Perisarc heavy, with thickened internal ridges

giving a corrugated appearance.

Primary hydrothecae sessile. Secondary hydrothecae with asymmetrical

pedicels which are curved or bent away from stem. Hydrotheca shallow, with

straight sides, widening slightly to margin, which is not everted, 0,03-0,04 mm

in depth and 0,13-0,17 mm in marginal diameter. Diaphragm delicate, with a

ring of refringent nodules about midway between diaphragm and margin. Walls

markedly thickened just below level of diaphragm, more so on adcauline side.

Hydranth with about 19 tentacles.

Male gonotheca unknown. Female gonothecae borne generally on hydro-

rhiza, occasionally on stem, in the latter case emerging from within the hydro-

thecae, laterally compressed, broadly oval in side view, smooth, with terminal

1S2 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 49.

Halecinum halecinum. A—D, hydrothecae; E, female gonophore.

Halecium inhacae. F, stem with female gonotheca; G, hydrothecae; H, female gonophore.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 153

aperture on adcauline side through which two hydranths emerge, containing a

single egg or planula.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only records: Inhaca Island,

littoral. 26/32 (1, s)

Halecium lankesteri (Bourne, 1890)

Fig. SOB-E

Haloikema lankesteri Bourne, 1890: 395, pl. 26 (figs 1-2).

Halecium lankesteri: Broch, 1933: 16, figs 3-4. Hamond, 1957: 302, figs 9-11. Vervoort, 1959:

221, figs 3-5. Millard, 1968: 257, fig. 1.

Diagnosis. Colony erect or stolonial. Erect stem reaching 5 mm in height,

unfascicled, branching irregularly, segmented, each internode giving rise to a

hydrotheca from an apophysis near the distal end, the apophysis and hydrotheca

lying in the same axis as the proximal part of the internode and the rest of

the internode bent sharply outwards and upwards, the stem thus geniculate with

the elbows below the nodes. Stem constricted at each node and immediately

above. Stolonial form with hydrophores arising direct from hydrorhiza, usually

regenerated many times.

Primary hydrothecae sessile. Secondary hydrothecae pedicellate. Pedicel

usually constricted immediately above origin, bulging above this, then widening

to distal end. Hydrotheca shallow, with straight sides, widening markedly to

margin, which is not everted, 0,02-0,04 mm in depth and 0,10-0,15 mm in

marginal diameter. Diaphragm delicate.

Gonothecae borne on stem or hydrorhiza. Male sausage-shaped, some-

times curved, smooth. Female similar to that of H. beanii, but shorter and

broader, curved, with obliquely distal-facing aperture on concave side, smooth,

with two fully-formed hydranths emerging from aperture, containing two or

three large eggs in a row.

Variation. Branching is very irregular and not necessarily in one plane. Branches

usually arise from the distal end of an internode and curve outwards and

upwards from the base, sometimes giving a dichotomous effect. The length of the

internodes is very variable and many irregularities occur.

Distribution outside South Africa. Adriatic Sea, North Atlantic, Mediterranean,

tropical West Africa. Type locality: Plymouth, England.

Distribution in South Africa. Mocgambique: Inhaca to Santa Carolina, inter-

tidal. 25/32 (1), 21/35

Halecium 2muricatum (Ellis & Solander, 1786)

Fig. SOA

Sertularia muricata Ellis & Solander, 1786: 59, pl. 7 (figs 3-4).

Halecium muricatum: Hincks, 1868: 223, pl. 43 (fig. 1). Jaderholm, 1909: 59, pl. 5 (figs 4-6).

Broch, 1909: 146, fig. 6. Millard, 1966a: 469, fig. 11A—B. Vervoort, 1972: 27, fig. 3b—d.

154 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis. Stems reaching 47 mm in height, fairly stiff, fascicled in basal region,

unbranched or branching in an irregularly pinnate fashion, segmented, usually

straight though sometimes weakly geniculate in distal region, each internode

giving rise to a hydrotheca from an apophysis near the distal end, the two rows

of hydrothecae in one plane. No annulation of internodes.

Primary hydrotheca pedicellate. Pedicel long (at least three times the depth

of the hydrotheca) and separated from the stem apophysis by a distinct node,

usually asymmetrical and more convex on adcauline side, containing at least

one and usually two pseudodiaphragmata. Secondary hydrotheca pedicellate,

the pedicel similar to that of the primary though shorter and usually with only

one pseudodiaphragm. Hydrotheca deep, widening to margin, which is strongly

everted, more so on adcauline side, 0,08—0,14 mm in depth and 0,2-0,3 mm in

marginal diameter. Diaphragm delicate, with a ring of refringent nodules

immediately above it.

Gonothecae (not reported from South Africa) similar in the male and

female, compressed-ovate, with radiating ridges bearing spines, without

hydranths.

Variation and remarks. The identification of this species cannot be certain until

confirmed by the gonothecae.

In the South African material the fascicled parts of the stems are matted

together in the lower part of the colony by coalescence or crossing over of the

superficial tubes. From this region graceful, unfascicled stems arise with regul-

arly alternating hydrothecae. These stems are either unbranched or branch in a

roughly pinnate manner. The branches may replace hydrothecae, but more

usually arise from the anterior or posterior face of a hydrothecal pedicel,

then curve to conform to the plane of the colony.

The node separating the primary hydrotheca from the stem apophysis is

sometimes incomplete.

Distribution outside South Africa. Arctic (circumpolar), North Pacific, North

Atlantic.

Distribution in South Africa. Rare on the south coast, from Table Bay to east

of Port Elizabeth in 0-46 m. 33/18 (s), 34/18 (s), 33/26 (s)

Halecium sessile Norman, 1867

Fig. 483K-M

Halecium sessile Norman, 1867: 196. Billard, 1904a: 157, pl. 6. Ralph, 1958: 331, figs 9h-i,

10c—d. Vervoort, 19665: 100, fig. 1.

Diagnosis. Stem reaching 25 mm, fascicled in lower part, branching irregularly,

segmented, geniculate, each internode giving rise to a hydrotheca from an

apophysis near the distal end. No annulation of internodes. Branches arising

from below hydrothecae.

Primary hydrotheca sessile, but with adcauline wall free from stem. Second-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 155

Fig. 50

Halecium ?muricatum. A, part of stem.

Halecium lankesteri. B and C, parts of stem with hydrophores; D, stem with female gonophore;

E, male gonophore.

Halecium tenellum. F anda G, female gonophores containing planulae; H, male gonophore;

J-L, parts of stem.

Scale in mm/10.

156 ANNALS OF THE SOUTH AFRICAN MUSEUM

ary hydrotheca pedicellate. Pedicel with one or two nodes near base, then

widening gradually to distal end. Hydrotheca shallow, with straight sides,

normally not widening to margin, which is not everted, 0,01-0,03 mm in depth

and 0,12-0,14 mm in marginal diameter. Secondary hydrotheca shallower on

adcauline than on abcauline side. A ring of refringent nodules about midway

between diaphragm and margin.

Gonothecae not reported from South Africa. Male elongated, smooth,

with rounded summit and no hydranths, bearing spermatogenic cells along

one side of spadix. Female kidney-shaped, short, with laterally facing aperture

on concave side, smooth, with two fully-formed hydranths emerging from

aperture, containing a single row of eggs or planulae.

Distribution. Cosmopolitan. Type locality: Hebrides.

Distribution in South Africa. Off Durban, in 425-430 m. 29/31 (d)

Halecium tenellum Hincks, 1861

Fig. SOF—L

Halecium tenellum Hincks, 1861: 252, pl. 6 (figs 1-4). Vervoort, 1959: 229, fig. 8. Millard,

1957: 193, fig. 5. Vervoort, 19665: 102, fig. 2. Millard, 1966a: 471, fig. 11C—F.

Diagnosis. Colonies small and usually epizootic on other hydroids, under 7 mm

in height. Stem unfascicled, slender, unbranched or sparsely branching, seg-

mented, geniculate. Hydrothecae arising from short apophyses of stem near the

distal ends of the internodes. A constriction usually present above and below

each node.

Primary hydrotheca sessile or with short pedicel. Secondary hydrotheca

pedicellate. Pedicel symmetrical or asymmetrical, constricted near base and

widening slightly to distal end. Hydrotheca shallow, with wall widening to

margin and strongly everted, 0,02-0,05 mm in depth and 0,11-0,17 mm in

marginal diameter. Diaphragm delicate, with a ring of refringent nodules

immediately above it.

Male and female gonothecae on separate colonies, arising from stem or

hydrorhiza. Male gonotheca compressed, smooth, elongate-oval in side view,

with pointed distal end, without hydranths. Female gonotheca compressed,

smooth, pear-shaped in side view, with terminal aperture on a papilla seated

in a circular depression, without hydranths, containing a cluster of 2-7 eggs or

planulae.

Variation. This minute species is extremely variable in its growth-form, yet

easily recognizable. The typical form has a regular geniculate stem with long,

slender internodes, each bearing a hydrotheca on its summit. Some of the South

African material is of this type, but more often the stem contains a number of

intervening athecate internodes, often a whole series one after another. In small

epizootic colonies a single hydrotheca often tops a stem made up solely of

athecate internodes, of which the terminal one resembles a secondary pedicel.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 157

Athecate internodes may be due to regeneration after injury and are especially

characteristic of this species. Regeneration by the production of tiers of

secondary hydrothecae is also very common.

Branches, when they occur, arise from below the hydrothecae and are often

as long as the main stem, giving a subdichotomous effect with an acute angle

between the limbs. Branches sometimes arise in pairs.

The hydrotheca is always small and delicate with the margin strongly

everted. The everted part is very thin and may be held straight out, curled under,

or is occasionally worn right off.

Distribution. Cosmopolitan. Type locality: Salcombe Bay, U.K.

Distribution in South Africa. Occurring irregularly along the south and east

coasts from False Bay to Mocambique, littoral to 120 m, with one deeper record

from Natal (495 m) by Vervoort (1966b). 34/18 (s), 35/19 (s), 34/22 (s), 34/23

(S53) 250(s)) 35/26 (d), 33/27 G), 32/28 (); 31/29 @), 29/31 Gd), 28/32 G),

25/32 (s), 26/32 (s)

Genus Hydrodendron Hincks, 1874

Syn. Ophiodes Hincks, 1866.

Diplocyathus Allman, 1888.

Phylactotheca Stechow, 1913.

Ophiodissa Stechow, 1919.

Diagnosis. Colony erect or stolonial. Erect stem usually bearing two rows of

alternate hydrothecae; divided into internodes, each with a hydrotheca-bearing

apophysis near distal end. Hydrotheca pedicellate, basin- or cup-shaped, with

delicate diaphragm and usually a ring of refringent nodules above it. Hydranth

constricted immediately below tentacles, with or without intertentacular web

between tentacle bases. Nematophores present, enclosed in one-chambered

nematothecae. Gonophores in the form of fixed sporosacs contained in gono-

thecae. Gonothecae solitary or, rarely (not in South African species), aggregated

into a coppinia.

Type species: Halecium gorgonoide G. O. Sars, 1874

KEY TO SPECIES

1. Colony stolonial (hydrophores arising from hydrorhiza) Bi ie ae ne os

— Colony with erect stem bearing hydrophores a ae ie (eS

2. Hydrophores cornucopia-shaped, each bearing one enn alice H. cornucopia

— Hydrophores deep-campanulate, nematothecae on hydrorhiza only H. caciniformis

3. Diaphragm straight; hydrotheca shallow, with diameter at least twice depth : 4

— Diaphragm oblique; hydrotheca deep, with diameter agree ale to depth

on deeper side ; 5

4. Hydrotheca Sees pulccly aon main cua al axis of stem. Gentine:

smooth or lightly corrugated ..__H. caciniformis

— Hydrotheca terminal, secondary hydrophore arising from lateral apophysis. Gono-

theca deeply annulated ahs , : ms H. sympodiformis

5. Nematothecae curved, one on each hydrothecal pedicel. : H. gracilis

Nematothecae Coes shaped, never on primary pedicel (though may 0 occur on regene-

rated pedicel) . ae si ie ny * es ae “) H. gardineri

158 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hydrodendron caciniformis (Ritchie, 1907)

Fig. 51

Ophiodes caciniformis Ritchie, 1907a: 500, pl. 23 (figs 11-12), pl. 24 (fig. 1), pl. 25 (fig. 5).

Diplocyathus caciniformis: Leloup, 1939: 4, fig. 3.

Hydrodendron caciniformis: Millard, 1957: 186, fig. 3. Ralph, 1958: 342, figs 13b-c, 14a.

Mammen, 1965a: 7, fig. 34. Millard, 19665: 490, fig. 1.

Ophiodissa caciniformis: Vervoort, 1959: 218, figs 1-2.

Diagnosis. Colony erect or stolonial, usually growing on weed. Hydrorhiza

reticulate; perisarc with internal projections. Erect stem under 10 mm in height,

unfascicled or weakly fascicled at base, occasionally branched, segmented, each

internode giving rise to a hydrotheca from an apophysis near the distal end.

The two rows of hydrothecae in one plane or shifted slightly onto anterior

face. Stolonial form with solitary hydrothecae arising directly from the

hydrorhiza and supported by 1-3 short internodes.

Hydrotheca pedicellate, often with regeneration nodes between the stem

apophysis and the pedicel. Pedicel deeper than hydrotheca, usually somewhat

turgid near base and expanding slightly towards distal end. Hydrotheca with

flaring wall and everted margin, 0,05—0,12 mm in depth and 0,14-0,2 mm in

marginal diameter. Diaphragm very delicate, straight. A ring of refringent

nodules usually about one third of the height above diaphragm. Hydranth with

19-23 tentacles.

Nematothecae borne on hydrorhiza, stem internodes or hydrothecal

pedicels, random in occurrence, sessile, goblet-shaped, with everted margin,

sometimes bilaterally symmetrical.

Gonotheca borne on hydrorhiza, elongated, widening to just below trun-

cated distal end, smooth or with rather indistinct transverse annulations, reach-

ing 0,8 mm in length and 0,3 mm in diameter.

Variation. The perisarcal projections in the hydrorhiza are not regular an are

more numerous in some regions than in others.

The erect form of the colony is more usual than the stolonial form, though

fair numbers of stolonial hydrothecae are often encountered among the erect

stems. Two entirely stolonial colonies have been found. Stronger stems have

been recorded from outside South Africa, and Ralph records strongly fascicled

stems of 22 mm with regularly subalternate branches arising below every third

and fourth hydrotheca from New Zealand. In some stems there is a suggestion

of an annulation in the form of a constriction above and below each node.

Secondary hydrothecae may arise from primary ones, not from within them

as in Halecium, but from the sides of the pedicels or the regenerated internodes

below them. This, indeed, is the way in which branches originate. Reduplicated

margins are very rare.

Pseudodiaphragmata may occur, particularly in regeneration internodes and

in the hydrothecal pedicels; they are usually better developed on the adcauline

side.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 159

Fig. 51.

Hydrodendron caciniformis. A, stem; B and C, parts of stem with hydrophores and nema-

tothecae; D and E, male and female gonophores (material from Vema Seamount);

F, living hydranths and nematophores.

Scale in mm/10.

160 ANNALS OF THE SOUTH AFRICAN MUSEUM

Observations on living material. The hydranths when fully extended are long

and tubular reaching 1,4 mm in length. The base is attached to the ring of refrin-

gent dots in the hydrotheca and narrows suddenly below to the coenosare

which passes through the opening in the diaphragm. There is always a distinct

space between the hydranth base and the diaphragm. The body of the hydranth

is narrowed distally immediately below the tentacles and this contracted ring

is visible even at full extension. The tentacles are held alternately elevated and

depressed and are connected to one another at the base by a web. They are very

mobile and may contract individually or all together. The hypostome is conical,

but very distensible. On contraction the tentacles close over the mouth and the

hydranth body is reduced to about half its length. It cannot be withdrawn into

the hydrotheca.

The nematophore reaches 2 mm in length when fully extended. It consists

of a solid core of endoderm cells and a covering of thin ectoderm and has a

terminal spherical knob well armed with nematocysts. The nematophores are

very mobile and are continually twisting about as though exploring the

surroundings.

As in many other hydroids the stem and hydrorhiza tend to produce abun-

dant stoloniferous processes under laboratory conditions. These are completely

enclosed in perisarc and well supplied with nematocysts. After four days in a

tank they reached 18 mm in length and were profusely branched. Many of them

arose from within dead hydrothecae.

Colour: transparent white.

Distribution outside South Africa. Cape Verde Islands (type locality), Mediter-

ranean, Portugal, West Indies, tropical West Africa, Vema Seamount

(S. Atlantic), Australia, New Zealand, India, Japan.

Distribution in South Africa. False Bay and Transkei coast, littoral to 17 m.

34/18 (1, s), 21/29 (1)

Hydrodendron cornucopia (Millard, 1955)

Fig. 52

Zygophylax cornucopia Millard, 1955: 219, fig. 3.

Hydrodendron cornucopia: Millard, 1973: 30, 33, fig. 6A-F

Diagnosis of typical form. Colony stolonial, epizootic on various species of

Antennella, Monostaechas and Corhiza (most common host: Antennella afri-

cana). Hydrorhiza giving rise directly to solitary hydrophores, each of which

is seated on a short basal internode. Hydrothecae facing alternately to right and

left, forming two rows more or less at right angles to one another and forming

an angle of about 45° with hydrorhiza.

Hydrophore (hydrotheca plus pedicel) with a cornucopia shape and double

curvature (first outwards, then upwards), widening gradually to margin, which

faces upwards (i.e. towards distal end of host), 0,3-0,4 mm in abcauline length

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 161

and 0,10-0,15 mm in marginal diameter. Pedicel more than twice length of

hydrotheca. Diaphragm oblique, with hydropore off-centre and closer to

‘upper’ side, a row of refringent nodules just above it. Hydranth just able to be

contained in hydrotheca, with about 18 tentacles and a constriction between

proximal digestive part and distal non-digestive part, no intertentacular web.

Nematotheca curved-barrel-shaped, one about halfway along ‘upper’ side

of each pedicel.

Gonothecae borne on hydrothecal pedicels close to nematothecae, elon-

Fig. 52.

Hydrodendron cornucopia. A, colony growing on Antennella africana; B, hydrophore with

nematotheca and female gonophore; C and D, two forms of branching hydrophores.

Scale in mm/10.

162 ANNALS OF THE SOUTH AFRICAN MUSEUM

gated, widening to truncated distal end. Male and female on separate hosts,

female larger than male and containing numerous eggs.

Variation. Although the hydrophores are normally solitary, branching indivi-

duals rarely occur. Branching occurs from the lateral surface of the pedicel,

either on one side only or on both sides. Such secondary hydrophores are

similar to the primary one, with basal segment and pedicel; they may branch

again several times.

Distribution. Endemic to South Africa. Type locality: False Bay.

Distribution in South Africa. South and east coasts, from Table Bay in the west

to Natal in the east, littoral to 86 m. 33/18 (s), 34/18 (1, s), 34/22 (s), 33/25 (s),

34/25 (s), 33/27 (s), 32/28 (s), 33/28 (s), 31/29 (s), 30/30 (s), 29/31 (s), 29/32 (s),

28/32 (s)

Hydrodendron gardineri (Jarvis, 1922)

Fig. 53A—D

Halecium gardineri Jarvis, 1922: 334, pl. 24 (fig. 1). Millard & Bouillon, 1974: 23, fig. 4.

Diagnosis. Colony erect or stolonial. Hydrorhiza reticulate; perisarc with

internal projections. Erect stem reaching 4 mm in height, unfascicled,

unbranched, segmented, each internode giving rise to a hydrotheca from an

apophysis arising near the centre or at about two-thirds of the length. The

two rows of hydrothecae in one plane. Stolonial form with solitary hydrothecae

arising directly from the hydrorhiza.

Hydrotheca pedicellate, often regenerated between the apophysis and the

pedicel resulting in additional nodes or corrugations. Pedicel deeper than

hydrotheca, slightly turgid near base, expanding evenly towards distal end to

merge into hydrotheca. Solitary hydrotheca usually with longer pedicel and

several regeneration nodes at base. Hydrotheca deep, widening to margin

which is usually everted, 0,11-0,16 mm in depth (adcauline) and 0,13-0,17 mm

in marginal diameter; diameter at margin approximately equal to adcauline

depth. Diaphragm oblique, sloping downwards to adcauline edge. No refringent

nodules. Hydranth just retractable into hydrotheca; with 18 tentacles and no

intertentacular web.

Nematothecae borne on hydrorhiza, stem internodes or regenerated parts

of thecal pedicels, irregular in occurrence, sessile, goblet-shaped, with everted

margin. Nematophore with a solid core of endoderm cells and a terminal

capitulum.

Gonotheca (not reported from South Africa) borne on hydrorhiza, male

cylindrical, with truncated distal end. Female unknown.

Distribution outside South Africa. Type locality and only record: Salomon,

Chagos, 109-220 m.

Distribution in South Africa. Mocambique: Inhaca to Inhambane, 2-3 m.

25/32, 24/35 (s)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 163

Fig. 53.

Hydrodendron gardineri. A and B, parts of erect colony; C and D, solitary hydrophores.

Hydrodendron gracilis. E, stem; F and G, hydrophores with nematothecae; H, female

gonophore with planulae; J, female gonophore with eggs.

Scale in mm/10.

164 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hydrodendron gracilis (Fraser, 1914)

Fig. 53E-J

Ophiodes gracilis Fraser, 1914: 171, pl. 22 (fig. 82).

Diplocyathus gracilis: Leloup, 1935: 11, fig. 2. Leloup, 1937: 17, fig. 9.

Zygophylax enigmatica Millard, 1964: 19, fig. 5A—-F.

Hydrodendron gracilis: Millard, 1973: 33, fig. 6F—E.

Diagnosis. Colony minute, epizootic on Nemertesia ramosa, with erect stems

reaching a height of 2-3 mm. Stem unfascicled, unbranched, segmented, each

internode giving rise to a hydrotheca from an apophysis near the distal end. The

two rows of hydrothecae in one plane. Each apophysis with a mamelon on

upper surface.

Hydrotheca pedicellate, usually with one or more regeneration nodes

between the stem apophysis and the pedicel. Pedicel 1,2-2,4 times length of

hydrotheca, expanding distally, with adcauline wall slightly convex near base.

Hydrotheca widening slightly to margin, 0,07-0,10 mm in height and 0,10—

0,11 mm in marginal diameter. Margin not everted. Diaphragm oblique, with

hydropore off-centre and closer to adcauline side. No refringent nodules.

Nematotheca curved, one about halfway along adcauline side of each

pedicel, and usually one on the distal end of each stem internode or on its

apophysis.

Gonothecae borne on the hydrocladial apophyses; female flattened, flask-

shaped in lateral view with slender neck and terminal aperture, containing about

nine eggs which develop into planulae in situ; male unknown.

Variation. The stem internodes vary in length, particularly near the base of the

stem where they tend to be much shorter. Weakly developed internodal septa

occasionally occur, both in the stem internodes and in the hydrothecal pedicels.

Remarks. This species shows some resemblances to the epizootic form of

Plumularia setacea. It can be distinguished from it by the fact that the hydrotheca

terminates the pedicel and is not seated on its anterior face and by the absence

of supracalycine nematothecae.

Distribution outside South Africa. West coast of North America (type locality),

West Indies, French Indo-China.

Distribution in South Africa. Reported once only, off the west coast of the Cape

Peninsula. 34/18 (s)

Hydrodendron sympodiformis Millard & Bouillon, 1974

Fig. 54

Hydrodendron sympodiformis Millard & Bouillon, 1974: 25, fig. 5.

Diagnosis. Colony erect or stolonial, growing on weed. Hydrorhiza reticulate;

perisarc with or without internal projections. Erect stem reaching a maximum

height of 7 mm, unfascicled, consisting of a series of hydrophores arising one

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 165

from another by sympodial branching, each hydrophore with a terminal

hydrotheca and a lateral apophysis which bears the next hydrophore, éach

hydrophore other than the first curved upwards to stand almost parallel to the

preceding one; hydrothecae not in one plane. Stolonial form with solitary

hydrophores arising directly from hydrorhiza.

Hydrothecal pedicel of variable length, often with regeneration nodes or

corrugations immediately above origin of apophysis in erect stem or at base

in solitary hydrophore. Hydrotheca with flaring wall, with margin sometimes

KC B,D,E

Fig. 54.

Hydrodendron sympodiformis. A, stem; B, part of stem; C, gonotheca; D, solitary hydrophore

and nematothecae; E, gonotheca.

Scale in mm/10.

166 ANNALS OF THE SOUTH AFRICAN MUSEUM

everted, 0,06-0,10 mm in depth and 0,17-0,2 mm in marginal diameter. Dia-

phragm straight. A ring of refringent nodules about midway between margin

and diaphragm. Hydranth with about 22 tentacles.

Nematothecae borne on hydrorhiza and hydrophore pedicels, random in

occurrence, sessile, goblet-shaped, with everted margin and perisarcal thickening

below it. Nematophore with terminal capitulum containing large nematocysts.

Gonotheca (only female known) borne on hydrorhiza, barrel-shaped with

widest part below centre, with 6—7 deep transverse annulations, reaching 0,8

mm in depth and 0,4 mm in maximum diameter.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only record: Inhaca, Mocam-

bique. 26/32

Family Lafoeidae

Diagnosis. Thecate hydroids with campanulate to tubular, and often bilaterally

symmetrical, hydrothecae, into which the hydranth can be completely with-

drawn. Hydrotheca stalked or adherent, without operculum, with untoothed

margin, with or without diaphragm. Hydranth with conical hypostome, one

circle of filiform tentacles and undifferentiated endoderm. Nematophores

present or absent. Gonophores enclosed in gonothecae, which are often aggre-

gated into a coppinia; in the form of fixed sporosacs or, rarely, producing free

medusae.

Introduction. The most primitive genera of the Lafoeidae are probably those

with stolonial colonies, as in Hebella and Scandia. Filellum also has stolonial

colonies, but the hydrothecae are adherent to the hydrorhiza for their proximal

part, then bend away from it. In all other species the mature colony consists

of an erect stem bearing hydrothecae, yet in most of them, and especially in the

genera Lafoea, Acryptolaria and Cryptolaria, a juvenile or epizootic form is

known which retains the stolonial arrangement. To separate the stolonial genera

into a separate family (the ‘Hebellidae’) which has been done by some systema-

tists, is therefore inadvisable.

The erect stem varies in complexity. It may be fascicled and the hydro-

thecae partly immersed. It may branch and rebranch, and there is little difference

between the orders of branches, since all bear hydrothecae, but for the sake of

uniformity the final branches are here termed hydrocladia.

In most genera the hydrotheca is supported by a slender pedicel, but

typically the two are not clearly demarcated externally. A diaphragm or an

annular thickening of perisarc may or may not separate them internally. In

the branching genera Acryptolaria and Cryptolaria the pedicel and hydrotheca

are partly adherent to the stem, but in young stolonial colonies the hydrothecae

are quite free. In this character these genera resemble Filellum.

Regeneration is common and may result in apparent segments in the stem

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 167

pedicel]

annular thickening

diaphragm

pedi

Pedice! nematotheca

STOLONIAL &

PEDICELLATE ERECT &

PEDICELLATE

STOLONIAL & ADHERENT ERECT & ADHERENT

Fig. 55.

Lafoeidae: types of hydrothecae.

or hydrocladia, or, more commonly, may produce new hydrothecae within

the old ones, giving the appearance of a margin which is reduplicated, often

many times (Fig. 56A). The measurements of hydrothecae which are given

are always without such supplementary margins.

Nematophores and nematothecae are present in the genera Cryptolaria

and Zygophylax. The nematothecae are usually minute tubular structures and

do not attain the complexity characteristic of many Plumulariidae.

The reproductive structure, the COPPINIA, 1s characteristic of the Lafoeidae,

and consists of a nest of closely packed gonothecae surrounding part of the stem

(Fig. 56F). It is usually protected by special defensive structures formed from

modified hydrothecae or nematothecae which project beyond the surface giving

to the whole a bristly appearance. Yet the more primitive “Hebellidae’ and

Cryptolarella have separate gonothecae. Hebella is the only genus known to

produce medusae, but the adult medusa is imperfectly known and in no species

has been reared to maturity.

Reproductive bodies are strangely scarce in the Lafoeidae and in some

species have never been recorded in this country. Since the final identification

often depends on these structures the specific name remains doubtful in such

cases and awaits confirmation at a later stage.

KEY TO GENERA

1. Hydrotheca stalked, not adherent .. i a th is Aes me 2

— Hydrotheca adherent ee ae 2 he Bes eit a2 ay 5

168 ANNALS OF THE SOUTH AFRICAN MUSEUM

2. Mature colony with erect, branching stem bearing hydrothecae irregularly

on all sides. Hydrotheca without diaphragm or annular thickening, not sharply

demarcated from pedicel. No nematothecae. Gonothecae aggregated into

coppinia sé Lafoea

— Colony erect or stolonial; erect stem bearing hydrothecae i in two longitudinal

rows. Hydrotheca usually with diaphragm or annular thickening (always in

South African species) ae By ak

3. Mature colony erect. Hydrotheca not sharply demarcated from pedicel, with

diaphragm. Nematothecae usually present (always in South African species).

Gonothecae usually aggregated into coppinia.. Zygophylax p.

— Colony stolonial. Hydrotheca distinctly demarcated from pedicel, usually with

annular thickening round base (always in South African species). No nemato-

thecae. Gonothecae single, never aggregated

4. Gonophores producing free medusae. Hydrotheca small, never over 1,2 mm in

height, usually much less... ote Hebella p.

— Gonophores in the form of fixed sporosacs. ‘Hydrothecae larger, 1 1—2,1 mm in

height .. ee ee 45 oe af be: a a oy Scandia p.

5. Colony stolonial. Hydrotheca adherent to hydrorhiza .. ae .. Filellum p.

Mature colony with erect, branching stem. Hydrotheca adherent to stem or

branch

6. Diaphragm present between hydrotheca and stem dees Nematothecae

present a wie D:

— Normally no diaphragm. No nematothecae

Ih Hydrothecae alternate, forming two longitudinal rows. Gonothecae aggregated

into coppinia : Acryptolaria p.

— Hydrothecae on all surfaces of stem, though they may ‘be alternate in some

regions. Gonothecae solitary, not aggregated = a es Cryptolarella p.

Genus Acryptolaria Norman, 1875

Syn. Scapus Norman, 1875.

Oswaldaria Stechow, 1923.

. 184

188

Diagnosis. Colony normally erect, stolonial in young stages. Erect stem fas-

cicled and branched; branches alternate or subalternate; stem and branches

bearing hydrocladia which are similar to the branches. Hydrothecae arising

from stem, branches and hydrocladia alternately in two rows and from the

axial tube when fascicled. Hydrotheca tubular, at least partly adnate, not

demarcated from apophysis and normally without a diaphragm. No nemato-

thecae, but reduced hydrothecae sometimes borne on accessory tubes (but not

in South African species). Gonothecae aggregated to form a coppinia.

Gonophores in the form of fixed sporosacs.

Type species: Acryptolaria andersoni Totton, 1930.

KEY TO SPECIES

1. Hydrotheca bent sharply outwards at almost a right angle. Abcauline wall with

distinct notch at level of bend : .. A. rectangularis

Hydrotheca curved smoothly outwards. No notch on abcauline wall . A. conferta

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 169

Acryptolaria conferta (Allman, 1877)

Fig. 56

Cryptolaria conferta Allman, 1877: 17; pl. 12 (figs 6-10).

Cryptolaria conferta var. australis Ritchie, 1911: 826, pl. 84 (fig. 2), pl. 87 (fig. 1).

Acryptolaria conferta: Millard, 1968: 260. Millard, 1973: 28, fig. 4C.

Acryptolaria conferta conferta: Millard, 1964: 7, fig. 1A—C, E.

Acryptolaria conferta australis: Millard, 1964: 9, fig. 1D, F—G. Vervoort, 19665: 115, fig. 15.

Diagnosis. Colony reaching a height of 110 mm. Stem of variable robustness,

fascicled, unsegmented, giving rise to alternate hydrothecae and irregularly

alternate branches or hydrocladia from the axial tube. Larger branches fas-

cicled, generally lying in one plane, each arising on a level with the free part of

a hydrotheca, giving rise to hydrothecae and hydrocladia in a similar manner.

Hydrocladia unfascicled or lightly fascicled, unsegmented, typically one to

every third hydrotheca. The two rows of hydrothecae in one plane.

Hydrotheca tubular, curved smoothly outwards, adnate for 4 to ? height

and rarely more, 0,5-1,3 mm in total adcauline length (adnate plus free part)

and 0,13—0,3 mm in marginal diameter (which is 14-24 times the diameter at

base). Margin very slightly everted.

Gonothecae aggregated into a coppinia, in contact with one another

though rather loosely packed, flask-shaped with slender distal neck and small

terminal orifice, producing acrocysts. Coppinia not provided with modified

hydrothecae or nematothecae.

Variation. Much variation in the growth-form occurs and colonies may vary

from small and flexuous to large and stiff. Irregularities in the branching may

produce shrubby growths often complicated by stolons which anastomose

with other regions.

The first hydrotheca on a hydrocladium is sometimes seated on the front

and thus in a plane at right angles to that of the stem, but after this the hydro-

cladium rotates until the original plane is restored.

Hydrothecae vary in size, though they never exceed a marginal diameter of

0,3 mm. Their spacing on the stem varies, and the base of the adcauline wall

may be well above the axil of the previous hydrotheca, level with it, or below it,

the last condition resulting in densely packed overlapping hydrothecae (Ritchie’s

var. australis). All grades between the two extremes occur. The abcauline wall

of the hydrotheca may be concave and evenly curved throughout, or may bulge

slightly near the base, when there may be a slight indentation below the hydro-

theca, giving the effect of a poorly developed node. Rejuvenations of the margin

are common.

Solitary hydrothecae may arise separately from the hydrorhiza in young

or epizootic colonies. These are erect, not adnate, and symmetrical or irregular

in shape.

Distribution. Cosmopolitan. Type locality: off Cuba.

Distribution in South Africa. Sparsely distributed from the west coast round the

170 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 56.

Acryptolaria conferta. A, part of stem of ‘var. conferta’; B, part of stem to show branching,

portions of peripheral tubes in position; C, solitary hydrothecae; D, young stem arising

next to a solitary hydrotheca; E, stem, heavy form; F, t.s. coppinia with female

gonothecae.

Scale: E in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 74)

Agulhas Bank into Natal and Mogambique, in 64 to 350 m. 30/15 (d), 35/19

(d), 35/22 (d), 34/23 (d), 34/24 (d), 33/27 (s), 30/31 (d), 29/31 (s, d), 24/35 (d)

Acryptolaria rectangularis (Jarvis, 1922)

Fig. 57A-D

Cryptolaria rectangularis Jarvis, 1922: 335, pl. 24 (fig. 3).

Acryptolaria angulata: Vervoort, 19666: 116, fig. 16.

Acryptolaria rectangularis: Millard, 1967: 174, fig. 2B. Millard, 1968: 261, fig. 2.

Diagnosis. Colony reaching a height of 70 mm. Stem flexuous (not able to sup-

port itself out of fluid), fascicled, unsegmented, giving rise to alternate hydro-

thecae and irregularly alternate or subalternate branches or hydrocladia from

the axial tube. Branches fascicled, given off more or less in one plane, each one

arising on a level with the top of a hydrotheca, giving rise to hydrothecae and

hydrocladia in a similar manner, commonly anastomosing with other parts of

the colony. Hydrocladia fascicled or unfascicled, unsegmented. The two rows

of hydrothecae in one plane.

Hydrotheca tubular, adnate for 3-2 length, then bent sharply outwards

forming almost a right angle with stem; free adcauline wall straight or slightly

concave; abcauline wall with distinct notch at point of divergence; 0,5—-1,3 mm

in total adcauline length (adnate plus free part) and 0,10—0,2 mm in marginal

diameter. The base of one hydrotheca commencing immediately above axil of

the one below. Margin slightly everted, directed outwards and upwards at an

angle to stem.

Gonothecae aggregated into a coppinia, firmly adpressed for complete

length, tubular, widening slightly to distal, wide, terminal aperture. Coppinia

provided with modified tubular hydrothecae which project above surface.

Variation. The branching in this species does not show the regularity common

to most of the family. Only rarely does any regularity occur, with two alternate

branches arising close together, and then it is usually after every fifth and sixth

hydrotheca. Also there are no axillary hydrothecae, a branch leaving the stem

immediately above, or next to, the axil of a hydrotheca.

The hydrotheca sometimes has an internal ring of tubercles for the attach-

ment of the base of the hydranth, which may be coalesced to form a diaphragm

in older parts of the colony. This character relates the species to the genus

Cryptolaria.

Solitary hydrothecae may arise separately from the hydrorhiza in young or

epizootic colonies; these are erect and without the right-angle bend, symmetrical

or irregular in shape.

Distribution outside South Africa. Providence, tropical Indian Ocean (type

locality) and south west Indian Ocean.

Distribution in South Africa. Off the coasts of Natal and Mocambique in 110

to 495 m. 30/31 (d), 29/31 (d), 26/33 (d), 24/35 (d).

172 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Cryptolarella Stechow, 1913

Diagnosis. Colony normally erect, stolonial in young stages. Erect stem fas-

cicled and branching. Hydrothecae arising from axial tube of stem irregularly

and on all surfaces. Hydrotheca tubular, partly adnate, without diaphragm.

No nematothecae. Gonothecae not aggregated, solitary or in pairs, contents

not known.

Type species: Cryptolaria abyssicola Allman, 1888.

One species only from South Africa.

Cryptolarella abyssicola (Allman, 1888)

Fig. 57E-G

Cryptolaria abyssicola Allman, 1888: 40, pl. 18 (figs 2—2a).

Cryptolarella abyssicola: Kramp, 1951: 121, pl. 1 (figs 1-3). Vervoort, 19665: 118, figs 18-20.

Diagnosis. Colony reaching a height of 60 mm. Stem flexuous (not able to

support itself out of fluid), fascicled, unsegmented, giving rise to hydrothecae

on all surfaces from an axial tube and to roughly alternate branches from the

peripheral tubes. Larger branches fascicled and similar to stem, often rebranch-

ing and reuniting by stolonic processess smaller branches unfascicled. Branch-

ing in one plane. Hydrothecae often partly buried by peripheral tubes, the base

of the adcauline wall usually below the axil of the preceding hydrotheca.

Hydrotheca tubular, adnate to stem for about half height, then curved

smoothly outwards, 0,6-2,3 mm in total adcauline height (adnate plus free

part) and 0,13-—0,2 mm in marginal diameter.

Gonothecae (not reported from South Africa) borne singly on stem,

flask-shaped, partly adnate, with a short curved neck.

Variation and remarks. This species has been found from two localities only,

and the specimens differ from one another rather markedly in hydrothecal size

and proportions but cannot be separated on any constant factor.

The colony with the large hydrothecae (1,8-2,3 mm in total adcauline

height and 0,16-0,2 mm in marginal diameter) comes from a greater depth

(2 740 m).

The colony with the small hydrothecae (0,6-0,7 mm in total adcauline

height and 0,13-0,16 mm in marginal diameter) comes from a lesser depth

(200 m). The hydrothecae are more closely set on the stem and the proportion

of marginal diameter to total adcauline length is greater (0,18-0,27 as against

0,07—-0,09). However, since the material described by Vervoort and Kramp

does, to a large extent, bridge the gap between the two samples, it is not justi-

fiable to create a new species for the form with small hydrothecae.

In both colonies the shape of the hydrotheca is variable and the free part

often abnormally elongated, possibly due to regeneration although no

regeneration lines are visible.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 173

Big.-57-

Acryptolaria rectangularis. A, part of branch; B, stem; C, t.s. part of coppinia with gonothecae

and modified hydrothecae; D, solitary hydrothecae.

Cryptolarella abyssicola. E, stem; F and G, parts of branches with small and large hydrothecae

respectively.

Scale: B and E in cm, the rest in mm/10

174 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. North Atlantic, East Indies, South Pacific.

Type locality: south of Australia, 42°42 'S/134°10’E, 4 740 m.

Distribution in South Africa. Off Saldanha Bay in 2 740 m and off Still Bay in

200 m. 33/16 (a), 35/22 @)

Genus Cryptolaria Busk, 1857

Syn. Perisiphonia Allman, 1888.

Diagnosis. Colony normally erect, stolonial in young stages. Erect stem fas-

cicled and branched; branches subalternate; stem and branches bearing hydro-

cladia which are similar to branches. Hydrothecae arising from stem, branches

and hydrocladia alternately in two or four longitudinal rows and from the

axial tube when fascicled. Hydrotheca tubular, at least partly adherent in at

least some part of colony, separated from apophysis by distinct diaphragm.

Nematothecae present. Gonothecae aggregated to form a coppinia. Gono-

phores in the form of fixed sporosacs.

Type species: Cryptolaria prima Busk, 1857 (syn. Perisiphonia quadriseriata

Trebilcock, 1928).

One species only from South Africa.

Cryptolaria pectinata (Allman, 1888)

Fig. 58A—F

Perisiphonia pectinata Allman, 1888: 45, pl. 21 (fig. 2). Ritchie, 1911: 835, pl. 87 (fig. 2).

Acryptolaria pectinata: Stechow, 1925a: 448, figs 20-21.

Cryptolaria pectinata: Ralph, 1958: 320, figs 5g—j, 6g-j, 7c.

Diagnosis. Colony reaching a height of 40 mm. Stem stiff, heavily fascicled,

branching in one plane, unsegmented, giving rise to alternate hydrothecae

and subalternate branches or hydrocladia from the axial tube. Branches fas-

cicled, similar to stem. Hydrocladia fascicled except at extremities, unsegmented,

arising below every third and fourth hydrotheca. The two rows of hydrothecae

in one plane.

Hydrotheca tubular; adnate for a variable proportion of length, usually over

half, but axillary hydrothecae often completely free from axial tube, those of

stem partly immersed in peripheral tubes; bent strongly outwards at beginning

of free part; with margin parallel to axial tube or tilted downwards; 0,3-0,4

mm in total adcauline length (adnate plus free part) and 0,06-0,10 mm in

marginal diameter. Diaphragm oblique, with abcauline edge higher than

adcauline.

Nematotnecae tubular, scattered irregularly on peripheral and axial tubes,

and usually one on each hydrothecal apophysis.

Gonothecae aggregated into a coppinia, flask-shaped, firmly adpressed

for about two-thirds of length and with slender, free neck provided with one or

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 175

two lateral openings and one or two curved, distal horns. Coppinia provided

with branched nematothecae which project above the surface.

Variation. Colonies of 130 mm have been reported from outside South Africa.

The arrangement of the hydrocladia is very regular and few deviations occur.

Although there is no segmentation, the hydrothecae, at any rate on young stems,

are usually distinctly grouped, there being a larger gap after every fourth one,

i.e. after every subalternate pair of hydrocladia.

The abcauline wall of the hydrotheca is thickened at the point of curvature

in older parts of the colony. Rejuvenations of the margin are common.

Solitary hydrothecae may arise separately from the hydrorhiza in young

or epizootic colonies; these are erect, not adnate, with a slender pedicel and

curved hydrotheca.

Remarks. The coppiniae in this species are dioecious. Stechow states that the

one-horned gonothecae are male and the two-horned ones female (containing

planulae). Yet Ralph has found eggs in one-horned gonothecae in New Zea-

land material (which I can confirm after examination). Only two-horned gono-

thecae have been found in South Africa and these contain bodies which resemble

planulae. The question of the sex thus needs confirmation.

Distribution outside South Africa. New Zealand (type locality), North Atlantic,

West Indies, ?Galapagos Islands.

Distribution in South Africa. East London to Natal in 49-90 m. 33/27 (s),

29/31 (s)

Genus Filellum Hincks, 1868

Syn. Reticularia Wyville Thompson, 1853

Diagnosis. Colony stolonial, with hydrothecae arising directly from a creeping

hydrorhiza. Hydrotheca tubular, adnate to hydrorhiza for part of its length,

then free, without diaphragm. Gonothecae aggregated to form a coppinia,

which also contains modified protective hydrothecae. Gonophores in the form

of fixed sporosacs. Generally no nematothecae.

Type species: Campanularia serpens Hassall, 1848

Remarks. The genus Filellum is common in South Africa, yet of the three

reported species only F. serratum is identifiable in the absence of coppiniae,

and coppiniae rarely occur.

KEY TO SPECIES

1. Adnate part of hydrotheca transversely ridged on outer surface. Coppinia with straight

accessory tubes ae, as ae fe vA Bee a a F. serratum

Adnate part of hydrotheca smooth. . oe ae bg e: ae ae we 2

2. Coppinia with forked accessory cubes a 4) te ni oe F. antarcticum

Coppinia with simple, curved accessory tubes .. Pe, - ee .. FF. serpens

176 ANNALS OF THE SOUTH AFRICAN MUSEUM

aoe

is Me

Fig. 58.

Cryptolaria pectinata. A, part of stem from distal region to show axillary hydrothecae and

origin of hydrocladia (the axial tube has thicker perisarc than the peripheral tubes);

B, t.s. part of coppinia showing female gonothecae and nematothecae; C, part of hydro-

cladium (only the axial tube shown); D, a young stem (the single peripheral tube not

shown); E, solitary hydrothecae; F, stem with coppinia.

Filellum antarcticum. G, hydrothecae; H, forked accessory tubes from coppinia.

Scale: F in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 177

Filellum antarcticum (Hartlaub, 1904)

Fig. 583G-H

Lafoéa antarctica Hartlaub, 1904: 11, pl. 2 (fig. 2). Vanhoffen, 1910: 311, fig. 3la-c.

Filellum antarcticum: Stechow, 1925b: 214. Millard, 1964: 10 (pp). non Millard, 1958: 175.

Reticularia antarctica: Totton, 1930: 160, fig. 17.

Diagnosis. Colony epizootic on other hydroids. Hydrotheca distinctly demar-

cated from hydrorhiza, adnate for +-} length, then free and bent outwards,

smooth, margin slightly everted, 0,10—0,12 mm in diameter.

Gonothecae aggregated into a coppinia, firmiy adpressed, cylindrical,

with terminal apertures, discharging their contents into acrocysts. Coppinia

provided with numerous forked accessory tubes (modified hydrothecae) which

arch over and protect the gonothecae.

Variation and remarks. A few of the hydrothecae show very faint transverse

striations on the outer surface of the adnate part. Reduplications of the margin

are common. Occasionally a few of the hydrothecae are not adnate at all, but

free for the entire length.

One example of a mutilated coppinia has been found, establishing for

certain the presence of the species in the country. Only this sample was used

for measurements. Infertile material of this species or F. serpens occurs quite

commonly.

Distribution outside South Africa. Antarctic (type locality), Australia, Chile.

Distribution in South Africa. The only certain record is from Mossel Bay on

the south coast in 13 m. Doubtful records from the Agulhas Bank and Natal.

34/22 (s)

Filellum ?serpens (Hassall, 1848)

Companularia serpens Hassall, 1848: 2223.

Filellum serpens: Hincks, 1868: 214, pl. 41 (fig. 4).

Coppinia arcta: Hincks, 1868: 219, pl. 41 (fig. 5).

Grammaria serpens: Vervoort, 1946a: 194, fig. 82.

Diagnosis. Colony generally epizootic on other hydroids. Hydrotheca tubular,

distinctly demarcated from hydrorhiza, adnate for 4-2 length, then free and

bent outwards, smooth, margin not or only slightly everted, about 0,1 mm in

diameter.

Gonothecae (not reported from South Africa) aggregated into a coppinia,

firmly adpressed, cylindrical, with terminal apertures. Coppinia provided with

numerous simple accessory tubes (modified hydrothecae) which curve over the

gonothecae. Coppinia hermaphroditic, containing male and female gonothecae.

{From Hincks and Vervoort.)

Distribution. Cosmopolitan. Type locality: U.K.

Distribution in South Africa. Uncertain. All previous records from the country

have been infertile, so there is a possibility of confusion with F. antarcticum.

178 ANNALS OF THE SOUTH AFRICAN MUSEUM

Filellum serratum (Clarke, 1879)

Fig. 59A—C

Lafoéa serrata Clarke, 1879: 242, pl. 4 (fig. 25). Hartlaub, 1905: 595, fig. Q?. Ritchie, 1911:

818.

Reticularia serrata: Ralph, 1958: 312, figs. 2), 3a.

Filellum 2antarcticum: Millard, 1958: 175. Millard, 1964: 10 (pp).

Filellum serratum: Millard, 1967: 175, fig. 2D. Vervoort, 1972: 51, fig. 14a—b.

Diagnosis. Colony generally epizootic on other hydroids. Hydrotheca tubular,

distinctly demarcated from hydrorhiza, adnate for 4—? length, then free and

bent outwards, adnate part transversely ridged on outer surface, margin slightly

everted, 0,10-0,3 mm in diameter.

Gonothecae aggregated into a coppinia, fatally adpressed, cylindrical,

with terminal apertures, releasing planula larvae. Accessory tubes present, at

least double the length of the gonothecae, unbranched, of very irregular shape

and usually curved or twisted.

Variation and remarks. Regenerations of the thecal margin are common. The

size of the hydrotheca and the proportion of its wall adnate are notoriously

variable. The striations also vary in number and distinctness (4-45 observed in

South Africa). Hartlaub reports nematothecae arising from the hydrorhiza in

material from South America. Occasionally a few of the hydrothecae rise erect

from the substratum with no adnate part.

The only previous description of the coppinia of this species is that of

Ritchie (1911), which unfortunately was not illustrated. Ritchie states that the

accessory tubes either “stand out stiffly from the surface... or‘... do not

project, but instead lie closely apposed to each other, parallel to the surface of

the coppinia’. The variability of the tubes can be confirmed.

The planulae appear to become trapped by the basket-work of the accessory

tubes and pour out when the coppinia is cut.

Distribution. Cosmopolitan. Type locality: Cuba.

Distribution in South Africa. Scattered, from the south-west Cape round the

Agulhas Bank to Natal and Mocambique, 24-347 m. 34/18 (d), 35/19 (d),

35/22 (d), 33/25 (s), 30/30 (s), 24/35 (d)

Genus Hebella Allman, 1888

Syn. Hebellopsis Hadzi, 1913.

Diagnosis. Colony stolonial, with stalked hydrothecae arising from a creeping

hydrorhiza. Hydrotheca cylindrical or deeply campanulate, distinctly demar-

cated from pedicel, usually with annular perisarcal thickening around base

(always in South African species), with or without a true diaphragm. Gono-

thecae arising singly from the hydrorhiza, producing free medusae. No

nematophores.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 179

i tity

Fig. 59.

Filellum serratum. A and B, hydrothecae illustrating extremes in size; C, t.s. part of coppinia,

showing gonothecae and accessory tubes, from the same colony as the small hydrothecae.

Hebella parvula. D, hydrothecae, redrawn from Stechow (1925a, as Hebellopsis parvula).

Hebella dispolians. E, colony infesting Amphisbetia maplestonei, redrawn from Warren (1909

as Lafoea dispolians).

Abbreviations: ep and pa: epizootic and parasitic parts of Hebella; ho: parts of host.

Scale in mm/10

180 ANNALS OF THE SOUTH AFRICAN MUSEUM

Medusae imperfectly known, with at least two marginal tentacles and no

cirri.

Type species: Hebella striata Allman, 1888.

KEY TO SPECIES

1. Hydrotheca very small (under 0,4 mm in height)

— Hydrotheca larger (over 0,5 mm in height)

2. Colony with epizootic and parasitic forms, the latter invading the perisarc of the host

and making use of its hydrothecae in place of its own. Epizootic form with cylindrical

hydrothecae of about 0,4 mm in height .. : : H. dispolians

— Colony with epizootic form only. Hydrotheca minute ‘(under 0,2 mm in height),

cylindrical BL = oe oe ee A a oh H. parvula

3. Colony with epizootic and parasitic forms, the latter invading the perisarc of the host

but producing its own hydrothecae. Hydrotheca expanding to margin, margin strongly

everted be so SA Shura

- Colony with epizootic form only. Hydrotheca eylindricall not expanding to margin,

margin not, or only very slightly, everted .. ae gi had ae H. scandens

Hebella dispolians (Warren, 1909)

Fig. 59E

Lafoea dispolians Warren, 1909: 105-112, figs 1-2, pl. 1.

Diagnosis. Colony epizootic and parasitic on Amphisbetia maplestonei, with the

hydrorhiza penetrating into the perisarc of the host or creeping over the surface.

Hydrotheca of epizootic form cylindrical, symmetrical or somewhat

irregular; margin not everted and perpendicular to axis; 0,4 mm in length and

0,18 mm in marginal diameter. Annular thecal thickening present. Pedicel

short, not annulated.

Hydrorhiza of parasitic form giving rise to hydranths which either utilize

the hydrothecae of the host or supplement them with short, terminal, perisarcal

collars.

Hydranth with eight tentacles.

Gonophores unknown.

Remarks. The parasitic form of this unique species gains entry through the

hydrothecae of the host, apparently killing the hydranths and replacing them

with its own. The hydrorhiza may penetrate into the coenosarc of the host; it is

normally without a perisarcal covering of its own, though the host tends to

secrete perisarcal partitions or tubes to isolate it. The growing tips are in direct

contact with the coenosarc of the host and can presumably obtain nourishment

from it.

Distribution. Endemic to South Africa. Type locality: Isipingo, Natal.

Distribution in South Africa. Not reported since Warren’s original description.

30/30

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 181

Hebella furax Millard, 1957

Fig. 60A-C

Hebella furax Millard, 1957: 200, fig. 8. Millard, 1964: 10, fig. 2B—D.

Diagnosis. Colony epizootic on plumulariid hydroids of the subfamily Aglao-

pheniinae, particularly Lytocarpus filamentosus, with the hydrorhiza sometimes

penetrating into the perisarc of the host as a parasitic form.

Hydrotheca of epizootic form deep-campanulate and usually asymmetrical,

smooth, with everted and slightly oblique margin, 0,6-1,2 mm in height and

0,4-0,6 mm in marginal diameter. Annular thecal thickening pronounced,

usually better developed on one side than the other. Reduplications of margin

common. Pedicel with 3-6 spiral annulations, 0,13-0,7 mm in length.

Hydrotheca of parasitic form emerging from hydrotheca or broken end of

hydrocladium of host, similar to epizootic form though generally smaller,

0,6-0,9 mm in height and 0,3-0,5 mm in marginal diameter. Pedicel usually

shorter than epizootic form, 0,03-0,17 mm in length, smooth or with one or

two spiral annulations.

Hydranth with about 17 tentacles.

Female gonotheca usually curved, trumpet-shaped, widening gradually

from a slender corrugated pedicel to a wide and everted margin, with smooth

or slightly corrugated walls, with cap-shaped operculum, 1,6—2,5 mm in total

height and 0,5—0,8 mm in marginal diameter. Containing several medusa-buds

one above the other. Medusa with at least three long marginal tentacles and a

four-lipped mouth.

Remarks. The species was named for the parasitic form, which was discovered

first (furax = thievish), though later it was found to be less common than the

epizootic form. The parasitic hydrorhiza apparently gains entry to the host

through the mamelon or through a damaged part of the perisarc. It has no peri-

sarcal covering of its own, making use instead of that of its host. The parasitic

pedicels acquire their own perisarcal covering on emergence, but they appear

to make use partly of the hydrothecae of the host, for they are usually shorter

than in the epizootic form. The infected parts of the host are always dead. No

gonophores have been observed to arise from parasitic hydrorhizae.

The parasitism in this species is not so extreme as in H. dispolians, for the

hydrorhiza does not invade the coenosarc of the host but runs alongside it.

Further the hydranths do not utilize the hydrothecae of the host to the same

extent. See also remarks on Scandia mutabilis.

Distribution outside South Africa. Seychelles.

Distribution in South Africa. South coast, from False Bay to East London, in

depths of 4 to 49 m. Off Natal and Mocambique, 2-42 m. Type locality:

False Bay. 34/18 (s), 34/21 (s), 34/22 (s), 33/25 (s), 33/27 (s), 32/28 (s), 30/30 (s),

26/32, 25/32, 25/33 (6); 24/35 (Ss)

182 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hebella paryula (Hincks, 1853)

Fig. 59D

Lafoéa parvula: Hincks, 1868: 203, pl. 40 (fig. 1).

Hebellopsis parvula: Stechow, 1925a: 441, fig. 16.

Diagnosis. Hydrotheca minute, cylindrical, of equal diameter throughout, less

than twice as deep as wide, smooth, symmetrical, margin not everted and per-

pendicular to axis, 0,16—-0,19 mm in height and 0,08 mm in marginal diameter.

Reduplications present. Annular thecal thickening present. Pedicel annulated,

with about four rings, 0,07 mm in length.

Gonophores unknown.

Distribution outside South Africa. Ireland (type locality), White Sea.

Distribution in South Africa. Reported once only by Stechow from the Agulhas

Bank in 100 m. 35/20 (d)

Hebella scandens (Bale, 1888)

Fig. 60F—G

Lafoea scandens Bale, 1888: 758, pl. 13 (figs 16-19). Warren, 1908: 341, fig. 21.

Hebella scandens: Millard, 1957: 202. Vervoort, 1967: 31, figs. 5-6.

Hebella calcarata: Ralph, 1958: 306, fig. la-s. Hirohito, 1969: 14, fig. 11.

Hebella urceolata Millard, 1964: 12, fig. 2A.

Diagnosis. Colony epizootic on other hydroids. Hydrotheca cylindrical, of

equal diameter or narrowing at or below margin, 24-34 times as deep as wide,

smooth or lightly corrugated, usually asymmetrical and bent slightly to one side,

margin not or only slightly everted and usually oblique, 0,5-1,0 mm in height

and 0,19-0,3 mm in marginal diameter. Annular thecal thickening present

and to it attached a thin diaphragm. Reduplications of margin common.

Pedicel smooth or corrugated, 0,12-0,3 mm in length. Hydranth with about 13

tentacles.

Gonotheca widening gradually from a slender pedicel to a wide margin

which is not everted, irregularly corrugated, with an operculum of four valves

inserted in four bays in the margin, 1,1-1,4 mm in total height and 0,4-0,5 mm

in marginal diameter. Containing up to four medusa-buds, one above the other.

Medusa at liberation with a simple mouth, two long, opposite marginal ten-

tacles, and rudiments of two other perradial tentacles and four interradial

tentacles. Adult medusa unknown.

Remarks. This is a very common species, epizootic on many species of Sertu-

lariidae, particularly Sertularella arbuscula, and also less commonly on Hale-

ciidae, Syntheciidae and Plumulariidae. It grows profusely and often completely

obscures the host.

One example has been seen in which the hydrorhiza penetrates the perisarc

of the host, where it loses its own perisarcal covering and runs side by side with

the coenosarc of the host, but this is apparently a rare condition.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 183

iaG

eos F

Fig. 60.

Hebella furax. A, hydrotheca of epizootic form; B, hydrotheca of parasitic form infesting

Lytocarpus filamentosus; C, gonotheca with medusa-buds.

Scandia mutabilis. D and E, hydrothecae.

Hebella scandens. F, hydrothecae; G, gonotheca with medusa-buds.

Scale in mm/10.

184 ANNALS OF THE SOUTH AFRICAN MUSEUM

The name of H. scandens is used for this species in preference to H. calcarata

for the reasons given by Rees & Thursfield (1965: 76).

In view of the discovery of intermediate forms H. urceolata has now been

sunk in the synonymy of H. scandens.

Distribution. Cosmopolitan. Type locality: East Australia.

Distribution in South Africa. Common all round the coast from Lambert’s Bay

on the west to Mocambique on the east, littoral and 0-164 m. 32/18 (s), 33/17

(s), 33/18 (1, s), 34/18 (1, s), 34/19 (s), 34/20 (s), 35/20 (d), 34/21 (s), 35/21 (d),

34/22 (s), 34/23 (s, d), 33/25 (s), 34/25 (s), 33/26 (s), 33/27 (s), 33/28 (s), 32/28

(s), 31/29 (Ss), 31/30 , s), 30/30 ¢, s), 30/31 G, d); 29/31 (G, d); 29/325G)e 28/22

(S5G)5-26/32(6) 5 25/325)25/33(s)> 24/35(6)323)/ 301) S235

Genus Lafoea Lamouroux, 1821

Diagnosis. Colony normally erect, rarely with stolonial form. Erect stem fas-

cicled and branching; stem and branches bearing hydrothecae from all sur-

faces. Hydrotheca cylindrical to deep-campanulate, usually asymmetrical,

free from stem, not distinctly demarcated from pedicel, with no diaphragm or

annular perisarcal thickening, but with a ring of refringent dots marking the

base of the hydranth. No nematothecae. Gonothecae aggregated to form a

coppinia, which also contains modified protective hydrothecae. Gonophores in

the form of fixed sporosacs.

Type species: Sertularia dumosa Fleming, 1820.

Remarks. The four South African species of this genus are extremely difficult

to distinguish as they tend to grade Into one another and combine features of

the accepted European species. The most common form agrees best with

L. fruticosa. L. benthophila was originally described as a large variety of

L. gracillima. L. gracillima and L. fruticosa have been united by Naumov. Totton

keeps them separate, although his figures of the hydrothecae of the two species

appear identical. L. dumosa is perhaps the most easily distinguished, though it is

possible that all the South African material should be included in one species.

For the present they have been kept separate as recorded in the literature, with

the hope that in time the problem will be clarified by the discovery of more

reproductive bodies. So far only one coppinia has been discovered (assigned to

L. fruticosa). a

The key which follows is based mainly on the conception of Broch and

Stechow, but is unsatisfactory in that it does not cover intergrading forms.

KEY TO SPECIES Ss

1. Hydrotheca held perpendicular to stem or branch, with no distinct pedicel, but merely

an indentation at base ag st i iB me “ie ue .. L. dumosa

— Hydrotheca held at an angle to stem or branch, with a distinct pedicel as toc ogee

2. Hydrotheca large, over 0,9 mm in height including pedicel ue ff L. benthophila

— Hydrotheca small, under 0,9 mm in height including pedicel .. me L. fruticosa

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 185

Lafoea benthophila Ritchie, 1909

Fig. 61G

Lafoea gracillima var. benthophila Ritchie, 1909: 76, fig. 2.

Lafoea benthophila: Stechow, 1925a: 455, fig. 24D. Vervoort, 19665: 124, fig. 27.

Diagnosis. Colony small, reaching a height of 18 mm. Stem fascicled in lower

parts, branching irregularly.

Hydrotheca pedicellate, forming an angle with stem, deep-conical and

expanding slightly to margin, curved outwards, large (1,0 mm in height includ-

ing pedicel, 0,2 mm in marginal diameter). Reduplications of margin common.

Pedicel short (0,14-0,15 mm), without definite annulations, smooth or with

1-3 weak spiral twists.

Coppinia imperfectly known (not recorded from South Africa). Gono-

phores producing acrocysts, protected by ‘spiral hydrothecae’ (Stechow).

Distribution outside South Africa. Antarctic (type locality), Mediterranean,

Arabian Sea, East Africa, southern Indian Ocean, Indo-Malayan region. A

deep-water species, 425-3 246 m.

Distribution in South Africa. Reported only once in 425-430 m off Natal by

Vervoort (19665). 29/31 (d)

Lafoea dumosa (Fleming, 1820)

Sertularia dumosa Fleming, 1820: 84.

Lafoea dumosa: Broch, 1909: 156, fig. 16. Siechon 1925a: 455, fig. 24A. Fraser, 1944: 221,

pl. 45 (fig. 205), pl. 46 (fig. 205).

Diagnosis. Colony stiff and bushy, reaching a height of 20 mm. Stem fascicled

in lower parts, branching irregularly.

Hydrotheca without definite pedicel, separated from stem by indentation

only and with only occasional indications of a spiral twisting, held more or less

perpendicular to the stem, deeply conical and widening to margin, scarcely

asymmetrical and curved only slightly outwards, 0,6-0,7 mm in height includ-

ing pedicel and 0,14-0,16 mm in marginal diameter. Reduplications of margin

occurring. Exists also in creeping form, with solitary hydrothecae arising direct

from hydrorhiza.

Coppinia (not recorded from South Africa) hermaphroditic, with closely

packed gonothecae and long, tubular, curved hydrothecae projecting above

them. Gonotheca hexagonal in section, with terminal aperture on short neck.

Distribution. Cosmopolitan. Type locality: Newhaven, England.

Distribution in South Africa. Reported only once in 106 m off Cape Town by

Stechow (1925a). 33/18 (d)

186 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 61.

Lafoea fruticosa. A, stem; B, part of fascicled stem to show branching; C, hydrothecae;

D, surface view of part of coppinia; E, t.s. part of coppinia, with gonothecae (one with an

acrocyst) and tubular hydrothecae; F, epizootic colony growing on an older colony.

Lafoea benthophila. G, hydrothecae, redrawn from Vervoort (19665).

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 187

Lafoea fruticosa (M. Sars, 1851)

Fig. 61A-F

Campanularia fruticosa M. Sars, 1851: 138.

Campanularia gracillima Alder, 1856: 361, pl. 14 (figs 5-6).

Lafoea gracillima: Broch, 1909: 156, figs 17-18. Stechow, 1925a: 457, fig. 24C. Vervoort,

19665: 125, fig. 28. .

Lafoea fruticosa: Broch, 1909: 158, fig. 19. Stechow, 1925a: 456, fig. 24B. Fraser, 1944: 223,

pl. 46 (fig. 206). Vervoort, 19665: 126, fig. 29. Millard, 1964: 14, fig. 3. Millard, 1967:

175, fig. 2C. Vervoort, 1972: 66, figs 19-21. Millard, 1973: 28, fig. 4A.

Diagnosis. Colony usually shrubby in appearance, though not stiff, reaching a

height of 90 mm. Stem and main branches fascicled, giving off branches

irregularly from the accessary tubes.

Hydrotheca pedicellate, forming an angle of 40-60° with stem, usually

deeply campanulate and asymmetrical due to a greater convexity on adcauline

wall, 0,5-0,9 mm in height including pedicel and 0,11-0,19 mm in marginal

diameter. Margin very slightly everted. Reduplications of margin common.

Pedicel 0,09-0,3 mm in length, with one or more spiral twists. Exists also in

stolonial form, with solitary hydrothecae arising directly from hydrorhiza.

Coppinia with closely packed gonothecae and very long, tubular, coiled

hydrothecae projecting above them. Gonothecae bottle-shaped with terminal

aperture on short neck, more or less hexagonal in section, producing acrocysts,

about 0,4 mm in height. Hydrothecae over 3 mm in length.

Variation. The branching follows no definite scheme, though in the distal

regions of the colony the branches do tend to be in one plane and often uni-

lateral. Stolons arising from the tips of the branches and anastomosing with

other regions may result in a matted and shrubby effect.

The hydrothecae show much variation in shape, even within the same

colony. Apart from the typical shape described above, some are very slender

with almost parallel walls, and some are shorter and more obviously

campanulate.

A pedicel is always distinct and is typically bent or twisted with two or

three kinks, one adcauline, the second abcauline, and sometimes a third less-

marked adcauline one.

Distribution. Cosmopolitan. Type locality: Norway.

Distribution in South Africa. Along the south and east coasts, from off Table

Bay in the west into Mocambique on the east, in 64 to 430 m. 33/18 (s), 34/18 (s),

35/20 (d), 35/22 (d), 34/23 (d), 33/27 (s), 29/31 (s, d), 29/32 (s), 28/32 (s, d),

24/35 (d)

Genus Scandia Fraser, 1912

Diagnosis. Colony stolonial, with stalked hydrothecae arising directly from a

creeping hydrorhiza. Hydrothecae deeply campanulate, distinctly demarcated

from pedicel, with an annular perisarcal thickening around base. Gonothecae

188 ANNALS OF THE SOUTH AFRICAN MUSEUM

arising singly from the hydrorhiza, containing fixed sporosacs. No nemato-

phores.

Type species: Campanularia mutabilis Ritchie, 1907.

One species only in South Africa.

Scandia mutabilis (Ritchie, 1907)

Fig. 60D-E

Campanularia mutabilis Ritchie, 1907a: 504, pl. 23 (figs 3-5).

Campanularia corrugata: Billard, 1907a: 341, fig. 1. Jarvis, 1922: 337, pl. 24 (fig. 5).

Lafoea magna Warren, 1908: 342, fig. 22.

Hebella corrugata: Broch, 1914: 30, fig. 6.

Scandia mutabilis: Fraser, 1944: 208, pl. 39 (fig. 187). Millard, 1957: 202. Millard, 1958: 176.

Diagnosis. Colony growing on weed and other hydroids. Hydrotheca large,

deep-campanulate and often asymmetrical, usually smooth, with strongly

everted and frequently oblique margin, 1,1—3,9 mm in height and 0,6—2,2 mm

in marginal diameter. Annular thecal thickening present. Pedicel with 3-11

spiral annulations, 0,2-4,2 mm in length. Hydranth with about 22 tentacles.

Gonotheca (not reported from South Africa) with short pedicel of one

segment; male smooth and pear-shaped; female elongate-oval with truncated

distal end, more or less corrugated, containing many eggs.

Variation. This species varies considerably in the size and shape of the hydro-

theca. Rarely a few shallow transverse corrugations occur. Reduplications of

the margin are sometimes present.

Remarks. The trophosome is very similar to that of Hebella furax and is dis-

tinguished only by the greater size of the hydrotheca. The dimensions in fact over-

lap, though the mean height of the hydrotheca in H. furax is 0,8 mm (68 measure-

ments) and in S. mutabilis 1,7 mm (51 measurements). The pedicel length is so

variable that it cannot be used as a distinguishing character, though it tends to

reach greater lengths in S. mutabilis.

Distribution outside South Africa. Atlantic Ocean from the West Indies to

tropical West Africa and Cape Verde. Indian Ocean from tropical East Africa

to Ambon. Type locality: Cape Verde Is.

Distribution in South Africa. False Bay, Cape, to Mocambique, littoral to 44

m. 34/18 (s), 34/21 (s), 34/23 (1), 33/26 (1), 30/30 (s), 26/32 (s), 25/32, 24/35 (s),

Z3/35(1):

Genus Zygophylax Quelch, 1885

Syn. Lictorella Allman, 1888.

Brucella Ritchie, 1907.

Diagnosis. Colony normally erect, rarely with stolonial form. Erect stem

fascicled or unfascicled, branched or unbranched; when fascicled, branches

arising from axial tube and usually subalternate. Stem (and branches when

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 189

present) bearing hydrocladia, which are often not distinguishable from branches.

Hydrothecae arising from stem, branches and hydrocladia alternately in two

rows and from the axial tube when fascicled. Hydrotheca free from stem or

hydrocladium, ‘pedicellate, not externally demarcated from its pedicel, but with

it forming a bilaterally symmetrical figure whose shape is characteristic of the

species, internally demarcated from pedicel by a diaphragm. Nematothecae

usually present (always in South African species). Gonothecae usually aggregated

to form a coppinia, which usually also contains modified protective hydrothecae

or nematothecae. Gonophores in the form of fixed sporosacs.

Type species: Zygophylax profunda Quelch, 1885.

KEY TO SPECIES

1. At least some of the hydrocladia forked .. Ly oe re:

— Hydrocladia never forked. Gonothecae, where known, ageregated into coppinia onyies

2. Pedicel less than 4 length of hydrotheca (usually +). Gonothecae in pairs, not forming

coppinia .. Z. geminocarpa

— Pedicel more than 3 4 length of hydrotheca (usually 4). Gonothecae unknown Z. ?geniculata

3. Hydrotheca cornucopia-shaped, with plane of margin turned towards adcauline side 4

— Hydrotheca deep-campanulate or tubular, with plane of margin at right angles to axis

or turned towards abcauline side .. ie “its te? ae <3 Ke ad 5

4. Hydrotheca and pedicel of about equal length .. an a ie Z. sibogae

— Hydrotheca about twice as long as pedicel FY. z .. Z. infundibulum

5. Hydrotheca large (diameter at mouth over 0,16 mm). Nera tethoeds only rarely present

on stem apophyses. Coppinia without nematothecae .. Z. antipathes

— Hydrotheca smaller (diameter at mouth under 0,17 mm). Nematothecae regularly

present on stem apophyses. Coppinia with modified nematothecae .. ae 6

6. Hydrotheca tubular, strongly curved outwards, slender (length 24-34 times aeneret at

mouth). Coppinia closed. Gonotheca with paired distal horns over-arching lateral

orifices. One nematotheca on each apophysis_ .... Z. africana

- EL Gun shorter and wider, asymmetrical but not markedly curved outwards (length

3-23 times diameter at mouth). Two nematothecae on each apophysis

7. Coppinia closed. Gonotheca with a single, short distal tube and terminal orifice Z. armata

Coppinia open. Gonotheca with two curved necks with terminal orifices Z. biarmata

Zygophylax africana Stechow, 1923

Fig. 62A—E

Zygophylax africana: Stechow, 1925a: 445, fig. 18. Millard, 1964: 15, fig. 4A—-F. Millard,

1973: 28, fig. 4B.

Diagnosis. Colony erect and branching, reaching a height of 100 mm. Stem

somewhat flexuous (not able to support itself out of fluid), fascicled, unseg-

mented, giving rise to alternate hydrothecae and subalternate branches or

hydrocladia from the axial tube. Larger branches fascicled, given off in one

plane and at a wide angle to the stem (70—90°), giving rise to hydrothecae and

hydrocladia in a similar manner. Hydrocladia lightly fascicled or unfascicled,

unsegmented, generally arising below every third and fourth hydrotheca.

The two rows of hydrothecae in one plane.

Hydrotheca and pedicel seated on a short apophysis, slender at base, then

190 ANNALS OF THE SOUTH AFRICAN MUSEUM

widening to a tubular structure which is curved definitely outwards, with

slightly everted margin, 0,3-0,4 mm in total adcauline length and 0,07-0,10 mm

in marginal diameter. Pedicel short, 7's- 3 length of hydrotheca. Diaphragm

oblique with abcauline edge higher than adcauline, with central hydropore.

Nematothecae tubular, normally one on each hydrothecal apophysis,

and irregularly scattered on hydrorhiza and peripheral tubes of stem.

Gonothecae aggregated into a coppinia, firmly adpressed to one another

for about ? length, then free. Each gonotheca widening from base to top of

contiguous portion, with free part slender and bearing two lateral orifices and

two distal divergent horns. Coppinia provided with long, branching nemato-

thecae, at least twice length of gonothecae, male and female similar.

Variation. The branching may show irregularities and occasionally an arrange-

ment whereby branches arise below every third hydrotheca. Anastomoses

between branches are common. Occasional transverse nodes may occur within

branches and hydrocladia. Axillary hydrothecae are shifted onto the apophyses

of the hydrocladia, as are their nematothecae. Reduplications of the thecal

margin are common.

Solitary hydrothecae may arise from the hydrorhiza or from young epi-

zootic colonies; these are curved as in the adult or quite symmetrical and straight.

Distribution. Endemic to South Africa. Type locality: off Cape Town, 33°41 ‘S/

18°0’E

Distribution in South Africa. West coast to Agulhas Bank in 137-363 m. 29/14

(d), 30/15 (d), 33/18 (d), 34/18 (d), 35/22 (d), 34/24 (d)

Zygophylax ?antipathes (Lamarck, 1816)

Fig. 62F-—G

Sertularia antipathes Lamarck, 1816: 115.

Lictorella halecioides Ailman, 1888: 35, pl. 17 (figs. 1-2).

Lictorella cyathifera Allman, 1888: 36, pl. 11 (figs 3—3a).

Lictorella antipathes: Billard, 1910: 6, fig. 1. Totton, 1930: 166.

Zygophylax antipathes: ?Millard & Bouillon, 1973: 62, fig. 8H. Watson, 1973: 164, fig. 9.

Diagnosis. Colony erect and branching, reaching a height of 47 mm. Stem

moderately stiff, fascicled, unsegmented, giving rise to alternate hydrothecae

and subalternate branches or hydrocladia from the axial tube. Larger branches

fascicled at base, given off in one plane and at almost right angles to the stem,

giving rise to hydrothecae and hydrocladia in a similar manner. Hydrocladia

unfascicled; unsegmented; generally arising below every third and fourth

hydrotheca. The two rows of hydrothecae in one plane or shifted slightly on to

the anterior surface.

Hydrotheca and pedicel seated on a short apophysis, deep-campanulate,

symmetrical or (more often) asymmetrical with the adcauline side more convex

than the abcauline, with slightly everted margin, 0,4-0,6 mm in total length

and 0,17-0,2 mm in marginal diameter. Pedicel 4-2 length of hydrotheca.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 191

Fig. 62.

Zygophylax africana. A, t.s. part of coppinia, with female gonothecae and branching nema-

tothecae; B, surface view of coppinia; C, solitary hydrothecae; D, part of fascicled stem

to show branching (branches cut off short); E, part of branch.

Zygophylax antipathes. F, basal part of hydrocladium with axillary and following two

hydrothecae; G, stem.

Scale: D and G in mm, the rest in mm/10.

192 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diaphragm thick, straight and at right angles to hydrothecal axis, with central

hydropore.

Nematothecae tubular, scarce, seated on hydrothecal apophyses, but only

one or two to a branch.

Gonothecae (not reported from South Africa) aggregated into a coppinia,

with hooded apertures and no protective nematothecae. (From Totton.)

Variation. Stems have been reported to reach as much as 120 mm outside South

Africa. The usual irregularities occur in the method of branching, and occa-

sional transverse nodes may occur in the stem and hydrocladia. Axillary hydro-

thecae are shifted on to the apophyses of the hydrocladia. The pedicel of the

hydrotheca is usually separated from its apophysis by a distinct node, but the

node is sometimes incomplete or absent altogether.

Remarks. The final identification of this species must await the discovery of

gonophores. It is closely related to Z. armata and Z. biarmata, differing from

them in the larger hydrothecae, stronger diaphragm and scarce nematothecae.

Distribution outside South Africa. Australasia (type locality: ‘mers australes ou

de la Nouvelle-Hollande’), East Indies, South Pacific (New Hebrides),

?Seychelles.

Distribution in South Africa. Off Natal and Mocambique in 6-110 m. 30/30 (s),

29/31 (s), 28/32 (s), 26/34 (s), 25/33 (s), 24/34 (s), 24/35 (d)

Zygophylax armata (Ritchie, 1907)

Fig. 63A—B

Brucella armata Ritchie, 1907b: 533, pl. 2 (fig. 2-2C).

Zygophylax armata: Millard, 1964: 18, fig. 4G. Rees & Thursfield, 1965: 77.

Diagnosis. Colony erect and branching, reaching a height of 42 mm. Stem stiff

and fascicled, unsegmented, giving rise to alternate hydrothecae and roughly

alternate branches or hydrocladia from the axial tube. Main branches fas-

cicled, given off in one plane and at an angle of 50-80° to stem, giving rise to

hydrocladia in a similar manner. Hydrocladia unfascicled or lightly fascicled,

unsegmented, each arising from immediately below a hydrotheca. The two rows

of hydrothecae in ohe plane or shifted onto the anterior surface.

Hydrotheca and pedicel seated on a short apophysis, slender at base, then

widening to an asymmetrical tubular structure with a convex adcauline wall

and a straight or slightly concave abcauline wall, 0,19-0,4 mm in total adcauline

length and 0,10-0,16 mm in marginal diameter. Pedicel short, #s-+ length of

hydrotheca. Diaphragm straight or slightly oblique, with central hydropore.

Nematothecae tubular, normally two on each hydrothecal apophysis (one

anterior and one posterior) and irregularly scattered on peripheral tubes of

stem.

Gonothecae (not reported from South Africa) aggregated into a coppinia,

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 193

flask-shaped with short and slender distal neck and terminal orifice. Coppinia

provided with numerous long, branching nematothecae. (From Ritchie.)

Variation. The branching is much more irregular than in other closely related

species of Zygophylax and only rarely does the subalternate arrangement

typical of so many Lafoeidae occur. A height of 60 mm has been reported from

outside South Africa. The margin of the hydrotheca is often slightly everted.

Solitary hydrothecae may arise separately from the hydrorhiza or from

epizootic colonies. These tend to be less bilaterally symmetrical than in the

adult, and are often quite irregular.

Remarks. Though the trophosome of this species agrees perfectly with the

original description, the identity cannot be absolutely certain until fertile

material is discovered.

Distribution outside South Africa. Off Gough Island in the South Atlantic (type

locality).

Distribution in South Africa. From the south-east coast of the Cape Province

northwards into Mocambique in 48-440 m. 33/27 (s), 33/28 (s), 30/31 (s),

29/31 (s, d), 29/32 (s), 28/32 (s, d), 24/35 (d)

Zygophylax ?biarmata Billard, 1905

Fig. 63C

Zygophylax biarmata: Billard, 1906: 180, fig. 8. Broch, 1918: 24.

2Zygophylax biarmata: Jarvis, 1922: 335. Millard, 1958: 176, fig. 4A. Millard, 1968: 263.

Diagnosis. Trophosome as in Zygophylax armata.

Gonothecae (not recorded from South Africa) aggregated into a loose (or

open) coppinia, ‘flattened-ovate, with an outward and downward curving neck

distally on either side in the transversal plane’. Coppinia richly provided with

nematothecae. (From Broch.)

Remarks. Z. biarmata is essentially a north Atlantic species. The coppinia was

described by Broch, though unfortunately not illustrated, from material from

Iceland. The coppinia is completely different from that of Z. armata, though

there seems little to distinguish the trophosomes. Infertile material recorded as

Z. biarmata from East Africa by Jarvis and from South Africa doubtfully

by Millard possibly all belongs to Z. armata. Z. biarmata is included here since

the possibility of its presence in the country cannot be disregarded. Only the

discovery of fertile material can settle the question.

Distribution outside South Africa. Bay of Biscay and Straits of Gibralter (type

locality), North Atlantic (Iceland to north-west Africa), ?Japan, ?Tropical East

Africa.

Distribution in South Africa. Dubious records from off Natal in 164-333 m.

230/31 (d), 229/31 (d)

194 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 63.

Zygophylax armata. A, part of hydrocladium; B, stem.

Zygophylax ?biarmata. C, hydrothecae.

Zygophylax geminocarpa. D, part of hydrocladium; E, cauline hydrotheca with nema-

tothecae; F, a pair of gonothecae; G, stem.

Scale: B, F and G in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 195

Zygophylax geminocarpa Millard, 1958

Fig. 63D-G

Zygophylax geminocarpa Millard, 1958: 177, fig. 4D-G.

Diagnosis. Colony erect and branching, reaching 110 mm. Stem and main

branches stiff, woody and heavily fascicled, giving rise to smaller, lightly

fascicled branches and unfascicled hydrocladia subalternately and in one plane.

Smaller branches giving off hydrocladia in a similar manner. Stem and branches

bearing alternate hydrothecae from the axial tube, usually three and one

alternately between consecutive branches or hydrocladia, those of the thicker

parts buried by the peripheral tubes. Hydrocladia bearing alternate hydrothecae;

either simple, with the two rows of hydrothecae in one plane; or forked at the

base in a plane at right angles to the normal plane of branching, with the two

rows of hydrothecae on each limb not in one plane but seated on the inner

surface of the fork. Branches and hydrocladia with occasional transverse nodes

at irregular intervals.

Hydrotheca seated on a short apophysis and a pedicel. Pedicel and hydro-

theca together widening fairly rapidly to form a bilaterally symmetrical figure

with a bulging adcauline wall and a more or less straight abcauline wall, and

with margin everted, more so on adcauline side; 0,4-0,5 mm in abcauline

length and 0,17—0,2 mm in marginal diameter. Pedicel about one quarter length

of hydrotheca. Diaphragm thick, with central hydropore.

Nematotheca tubular, swollen at or below margin, two-chambered, with

basal chamber very small; 1-4 (usually 2) on each hydrothecal apophysis, and

irregularly scattered on peripheral tubes of stem.

Gonothecae not aggregated into coppinia, but attached in pairs (rarely

single), these pairs occurring in dense clusters around certain areas of stem and

main branches. Gonotheca elongated, tapering to tip, round in section, fused

to its twin for about ? length, then free, bearing scattered nematothecae on

lower part.

Distribution. Endemic to South Africa. Type locality: off Port Shepstone, Natal.

Distribution.in South Africa. Reported only once as above. 30/30 (s)

Zygophylax ?geniculata (Clarke, 1894)

Fig. 64

Lictorella geniculata Clarke, 1894: 74, pl. 3.

Zygophylax geniculata: Leloup, 1940: 13, pl. 1 (fig. 9).

Zygophylax ?geniculata: Millard, 1968: 264, fig. 3.

Diagnosis. Colony erect and branching, reaching a height of 50 mm. Stem stiff,

fascicled, unsegmented, giving rise to alternate hydrothecae and subalternate

branches or hydrocladia from the axial tube. Branches fascicled, given off in

one plane and almost at right angles to stem, giving rise to hydrocladia in a

similar manner. Hydrocladia unfascicled or lightly fascicled at base; with distant

196 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 64.

Zygophylax ?geniculata. A, part of stem and hydrocladia (some forked); B, hydrocladium;

C-E, hydrothecae and nematothecae (the third hydrotheca is axillary).

Scale: A in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 197

and irregular transverse nodes; generally arising below every third and fourth

hydrotheca of stem; bearing alternate hydrothecae; often subdichotomously

forked at the base in a plane at right angles to the normal plane of branching,

the anterior limb of the fork being less well developed than the posterior. The

two rows of hydrothecae in one plane or shifted towards the anterior surface,

those of the anterior limb of a forked hydracladium shifted towards the posterior

surface.

Hydrotheca and pedicel seated on a short apophysis from which they are

separated by at least one internode bounded by transverse nodes. Pedicel and

hydrotheca slender proximally, widening just beyond diaphragm where the

adcauline wall is usually more convex than the abcauline, slightly constricted

just below margin; 0,4—0,5 mm in length and 0,11—0,15 mm in marginal diameter.

Margin slightly everted and perpendicular to axis. Pedicel 3-7 length of hydro-

theca and forming an angle of up to 70° with stem. Diaphragm delicate, straight

or oblique, with central hydropore.

Nematothecae tubular, scarce, on peripheral tubes of stem, apophyses of

hydrocladia and apophyses of hydrothecae.

Gonothecae unknown.

Remarks. The material assigned to this species shows certain differences from

the type material, viz. the presence of a segment below the hydrothecal pedicel,

the forking of some hydrocladia and the presence of nematothecae. It is close to

Z. bifurcata Billard, 1942, from the Isle of Timor. This species has bifurcated

hydrocladia throughout and very similar nematothecae, but the pedicel of the

hydrotheca is much longer and the hydrotheca larger. Final identification must

await further material and gonothecae.

Distribution outside South Africa. Gulf of Panama (type locality), Azores.

Distribution in South Africa. Reported only once from off the Cape Peninsula

in 287 m. 34/18 (d)

Zygophylax infundibulum Millard, 1958

Fig. 65D-E

Zygophylax infundibulum Millard, 1958: 180, fig. 4B—C.

Diagnosis. Colony erect and branching, reaching a height of 60 mm. Stem

moderately stiff, fascicled, unsegmented, giving rise to alternate hydrothecae

and subalternate branches or hydrocladia from the axial tube. Branches fas-

cicled, given off in one plane and at a wide angle to the stem (50-60°), giving

rise to hydrothecae and hydrocladia in a similar manner. Hydrocladia unfas-

cicled or lightly fascicled, unsegmented; generally arising below every third

and fourth hydrotheca; bearing alternate hydrothecae. The two rows of hydro-

thecae not in one plane but on anterior surface, with an acute angle between

them and with the members of one row rotated so that they face slightly away

from those of the other row.

198 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hydrotheca and pedicel seated on a short apophysis; widening gradually

to margin; together with a cornucopia shape and double curvature (first out-

wards, then upwards), 0,6-0,7 mm in total length and 0,11—0,14 mm in marginal

diameter. Pedicel about half length of hydrotheca. Diaphragm well formed,

markedly funnel-shaped, better developed on abcauline side and with

hydropore slightly off-centre.

Nematothecae elongate-oval, one on each hydrothecal apophysis.

Gonothecae unknown.

Variation. Many irregularities occur in the method of branching and the inter-

vals between consecutive hydrocladia. Rare transverse nodes occur in the

hydrocladia, midway between two hydrothecae. The hydrotheca in the axil of a

hydrocladium is shifted on to the apophysis of the latter, and its nematotheca is

not on its own apophysis but on that of the hydrocladium. Regeneration is

common, especially within the pedicel and lower part of the hydrotheca.

Distribution. Endemic to South Africa. Type locality: off Natal.

Distribution in South Africa. Reported twice off Natal in 155-219 m. 29/31 (d)

Zygophylax sibogae Billard, 1918

Fig. 65A—C

Zygophylax sibogae Billard, 1918: 21, fig. 1. Totton, 1930: 167, fig. 21. Ralph, 1958: 311,

fig. 2e-i. Millard, 1964: 21, fig. SG—H.

Diagnosis. Colony erect and branching, reaching a height of 30 mm. Stem stiff,

fascicled, unsegmented, giving rise to alternate hydrothecae and subalternate

branches or hydrocladia from the axial tube. Branches fascicled, given off in one

plane and at a wide angle to the stem (50-70°), giving rise to hydrothecae and

hydrocladia in a similar manner. Hydrocladia unfascicled or lightly fascicled,

unsegmented; generally arising below every third and fourth hydrotheca;

bearing alternate hydrothecae. The two rows of hydrothecae not in one plane

but borne on anterior surface, with an acute angle between them and with the

members of one row rotated so that they face slightly away from those of the

other row.

Hydrotheca and pedicel seated on a short apophysis: slender and tubular

for the proximal half, then widening and strongly recurved towards distal end

of colony in the manner of a cobra’s hood, 0,5—0,6 mm in total length and 0,11-

0,13 mm in marginal diameter. Pedicel of approximately same length as hydro-

theca. Diaphragm well formed, often funnel-shaped, with central hydropore.

Nematothecae tubular, on the peripheral tubes and one on each hydrothecal

apophysis.

Gonothecae (not reported from South Africa) aggregated into a coppinia

in which some are tightly packed and some quite free, the whole provided with

modified protective nematothecae. Free gonotheca spherical, with two recurved

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 199

Fig. 65.

Zygophylax sibogae. A, stem; B and C, part of hydrocladium in ventral and anterior view

respectively.

Zygophylax infundibulum. D, stem; E, hydrocladium.

Scale: A and D in mm, the rest in mm/10.

200 ANNALS OF THE SOUTH AFRICAN MUSEUM

distal extensions with terminal apertures. Fused gonothecae more variable and

irregular.

Distribution outside South Africa. Dutch East Indies (type locality), New

Zealand.

Distribution in South Africa. Reported once only, from the Agulhas Bank off

the south-east coast in 88 m. 33/27 (s)

Family Campanulariidae

Diagnosis. Thecate hydroids with campanulate or cup-shaped hydrothecae,

which may be radially or bilaterally symmetrical and into which the hydranth

may or may not be completely withdrawn. Hydrotheca stalked, without oper-

culum, with toothed or untoothed margin, divided into a small proximal and a

large distal hydranth-containing region by a diaphragm or annular thickening

of the perisarcal wall. Hydranth with trumpet-shaped hypostome, one circle of

filiform tentacles and homogeneous endoderm. Nematophores absent. Gono-

phores in the form of fixed sporosacs or free medusae.

Medusa when present, with small stomach, no peduncle, usually four

simple radial canals, no excretory pores, hollow or, rarely, solid marginal

tentacles, no cirri, closed statocysts (marginal vesicles), no ocelli. Gonads

borne on radial canals separated from stomach.

Introduction. Among the Campanulariidae the colony may be stolonial or erect.

The erect stem is in reality a sympodium in which each hydrotheca arises,

alternately on the right and the left, from the base of the one below it, and is

characteristically GENICULATE or zigzag. Branching commonly occurs, branches

usually arising next to the hydrothecal pedicels, and normally of much the

same strength as the stem itself. This results in feathery colonies with no thick

and obvious main stem. Fascicled stems are comparatively rare. The stem is

usually divided into internodes, each bearing a hydrotheca.

The hydrothecae are pedicellate, and the pedicels may be smooth, roughly

corrugated or distinctly annulated. In the genus Campanularia there is always

one distinct ‘spherule’ at the distal end of the pedicel, usually of a smaller

diameter.

The hydrotheca is typically CAMPANULATE, or inverted bell-shaped, though

variations do occur, some being almost tubular, others cup-shaped, and some

distinctly bilaterally symmetrical. The basal part of the cavity of the hydrotheca

is separated from the distal part containing the hydranth by a diaphragm or

analogous structure. In the genera Clytia, Obelia, Gonothyraea and Eulaomedea

a true DIAPHRAGM is present in the form of a thin perisarcal shelf on which the

base of the hydranth rests. This diaphragm is usually exceedingly delicate, but

occasionally, as in Obelia geniculata and some species of Clytia, it may be

thickened and almost triangular in section. In the genera Campanularia and

Silicularia there is no true diaphragm, but instead an ANNULAR THICKENING of

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 201

the perisarcal wall, to the upper surface of which the base of the hydranth is

attached. This thickening may be either very marked or inconspicuous.

In the genus Silicularia and in certain species of Campanularia (previously

included in a separate genus Orthopyxis) the walls of the hydrotheca may be

grossly thickened. This thickening typically occurs on two opposite sides

imparting a bilateral symmetry to the hydrotheca and an oval rather than a

circular cross-section. In the relevant Campanularia species this thickening is

not sufficient to prevent the complete withdrawal of the hydranth into the

cavity. The thickening appears to be a potentiality rather than an invariable rule,

and thickened, bilaterally symmetrical hydrothecae may occur side-by-side

with unthickened, radially symmetrical ones. For this reason it is not logical to

retain a separate genus Orthopyxis. In Silicularia the thickening is always present

and is developed to such an extent that the cavity can no longer contain the

retracted hydranth. Furthermore the bilateral symmetry is more pronounced,

one side of the thecal margin being higher than the other.

simple teeth —bilobed THICKENED WALLS

teeth

annular thickening

diaphragm

— terminal spherule

—annulations

USE

Fig. 66.

Campanulariidae: structure and types of hydrothecae.

The reproduction in the Campanulariidae is very variable, and all grades of

gonophore from fixed sporosacs to free-swimming medusae occur. This has been

the cause of much disagreement on the limitation of genera, some authors basing

the classification on the trophosome only and ignoring the reproductive bodies

and others creating different genera for all different types of reproductive body.

Following the practice in this monograph separate genera are retained for forms

with fixed sporosacs and forms with free medusae, including for this purpose

the various grades of degenerate medusae from the styloid to the eumedusoid

type with the fixed sporosacs. The difficulty is that it may be necessary to have

fertile material in order to delegate it to its genus and species. Infertile colonies

of Obelia, Gonothyraea and Eulaomedea, for instance, are very similar in

appearance.

The names of the various grades of degenerate medusae are defined on

p. 18, and examples of all these types can be found among the Campanulariidae.

Occasionally more than one type may occur within the same species. In Cam-

panularia integra, for instance, it has long been known that the gonosome

202 ANNALS OF THE SOUTH AFRICAN MUSEUM

may produce either fixed sporosacs, in which the eggs and planulae are retained

in the gonotheca, or eumedusae with a short free-living existence (Agastra).

It was thought that the difference was dependent on the season of the year, yet

in South Africa the two types have been found within a single colony and at the

same time. The control of the process is clearly not yet understood. In some

species there is a sexual difference in the type of reproductive body; thus in

Eulaomedea flexuosa the male gonophores are styloid and the female heterome-

dusoid.

Two genera which produce fully-formed medusae, namely Clytia and

Obelia, have very similar trophosomes, differing only in the stolonial colonies of

the former and the erect stems of the latter. The medusae, however, are very

different, those of C/ytia being hemispherical with hollow marginal tentacles and

a well developed velum, and those of Obelia shallow saucer-shaped, with solid

marginal tentacles and a reduced velum. These two genera must thus remain

separate.

The genus Gonothyraea is closely related to Eulaomedea, which has fixed

sporosacs, but can be retained as a separate genus on the grounds of its unusual

reproductive bodies, which are of the eumedusoid type and are extruded

through the opening of the gonotheca. where they hang in clusters until the

planulae are released. These medusiform bodies, which have comparatively

well developed marginal tentacles, are known as MECONIDIA (Fig. 74C-—F).

Two genera of doubtful affinities have been omitted from the following key;

they are not known in South Africa. Billardia Totton, 1930, placed in the

Campanulariidae by Totton and by Ralph (1957), shows relationships with the

Lafoeidae (in the curved bilaterally symmetrical hydrothecae) and with the

Syntheciidae (hydrothecae sometimes slightly adnate). Tulpa Stechow, 1921

is distinguished from Campanularia only by the greater size and characteristic

shape (tulip-shape) of the hydrotheca.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Colony stolonial a : 2

— Colony with an erect stem, bearing alienate hydrothecae. Hydrotheca with

true diaphragm, which is distinctly demarcated from its wall .. ae a 4

2. Hydrotheca with true diaphragm, which is distinctly demarcated from its wall.

Producing free medusae a Clytia p. 213

— Hydrotheca without true diaphragm, but with an ‘annular perisarcal thickening

near base. Producing fixed sporosacs, which may rarely take the form of

degenerate, short-lived medusae without stomach or marginal tentacles ne 3

3. Hydranth completely retractable into hydrotheca. Hydrotheca usually radially

symmetrical, occasionally thickened and with bilateral tendencies | Campanularia p. 203

— Hydranth not completely retractable into hydrotheca. Hydrotheca always bila-

terally symmetrical and grossly thickened he af at [ Silicularia]

4. Gonophores released as free medusae

— Gonophores not released as free medusae

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 203

5. Medusa shallow, with 16 marginal tentacles, 8 eat and a rudimentary velum

on liberation .. so Obelia p. 226

— Medusa deep, with 4 ‘marginal tentacles, numerous statocysts and a normal velum

on liberation .. ce Bic 3 of br a 2s oy Clytia p. 213

6. Gonophores forming degenerate medusae (meconidia) which are discharged into

acrocysts where they become sexually mature... . Gonothyraea p. 224

— Gonophores in the form of fixed sporosacs or degenerate medusae which do not

leave the gonotheca .. a. ae ne Ps, oe nf Eulaomedea p. 223

Genus Campanularia Lamarck, 1816

Syn. Orthopyxis L. Agassiz, 1862.

Eucopella von Lendenfeld, 1883.

Agastra Hartlaub, 1897.

Diagnosis. Colony stolonial; hydrothecal pedicel unbranched, with at least

one terminal spherule. Hydrotheca campanulate or funnel-shaped, usually

radially symmetrical but sometimes grossly thickened on two opposite sides,

with toothed or untoothed margin. An annular perisarcal thickening present

inside base of hydrotheca. Hydranth completely retractable into hydrotheca.

Gonotheca borne on hydrorhiza, containing fixed sporosacs or degenerate

medusae (eumedusae) which may rarely have a short free-swimming life.

Eumedusa, when present, without stomach, usually without marginal tentacles,

with four radial canals and eight closed statocysts.

Type species: Sertularia volubilis Linnaeus, 1758.

KEY TO SPECIES

1. Margin of hydrotheca never toothed. Perisarc capable of great thickening .. C. integra

— Margin toothed in at least some hydrothecae ... yi te Es es Sen ieenlD:

2. Marginal teeth double or truncated a be - i, C. hincksii

— Marginal teeth single; pointed or rounded ~ Er eae = st by penis

3. Perisarc never markedly thickened ‘ , - Bs “6 aud biled,

— Perisarc of at least some hydrothecae grossly thickened oy or = aT a

4. Hydrotheca with raised rim below margin. Gonotheca annulated ~ C. morgansi

— Hydrotheca without raised rim. Gonotheca not annulated as es ce wr eS

5. Colony epizootic on Thyroscyphus. Gonotheca laterally compressed .. C. laminacarpa

— Colony growing on weed. Gonotheca round in section fe: an C. africana

6. Gonotheca scallop-shaped, opening around periphery .. b oe on in eet |

— Gonotheca not scallop-shaped, with terminal opening .. <2 A om a:

7. Hydrotheca asymmetrically thickened on the two sides. Gonophores in the form of

fixed sporosacs é a4 1Caroberti

— Hydrotheca symmetrically thickened on two opposite sides. Gonophores eumedusoid

with a short free-living life .. = ik oe at on me 1. @2pecten

8. Most hydrothecae compressed, with low, rounded marginal teeth. Pedicel deeply and

spirally grooved. Gonotheca compressed, widest at distal end . ; .. C. crenata

— Hydrotheca not, or only slightly, compressed, with deeper, triangular marginal teeth

Pedicel closely annulated at both ends, smooth between. Gonotheca not compressed,

widest near centre .. a. ee + as, or + ae C. ?delicata

204 ANNALS OF THE SOUTH AFRICAN MUSEUM

Campanularia africana Stechow, 1923

Fig. 67A

Campanularia tincta: Warren, 1908: 337, fig. 18.

Campanularia africana Stechow, 19236: 104.

Diagnosis. Colony growing on weeds and other hydroids, reaching 3 mm in

height. Hydrothecal pedicel smooth or corrugated, with one spherule of smaller

diameter at distal end.

Hydrotheca deep-campanulate, with almost parallel sides, 0,5-0,8 mm

in depth and 0,3-0,5 mm in marginal diameter. Margin with 10-12 rounded

teeth separated by rounded bays of approximately thesame size. Hydranth

with about 25 tentacles.

Gonotheca borne on hydrorhiza, cylindrical to ovate, round in section,

smooth or with irregular corrugations, narrowing slightly towards distal end,

then widening to low, everted collar around circular terminal aperture. Female

containing eggs or planulae.

Remarks. Sterile colonies of this species cannot be distinguished from

C. laminacarpa.

Distribution outside South Africa. Australja, Japan.

Distribution in South Africa. Natal, littoral to 48 m. Type locality: Park Rynie.

30/30 (1), 28/32 (s)

Campanularia crenata (Hartlaub, 1901)

Fig. 68A—F

Eucopella crenata Hartlaub, 19015: 364, pl. 22 (figs 27-31, 33-35). Hirohito, 1969: 7, fig. 7.

Orthopyxis crenata: Ralph, 1957: 838, fig. 6g—v.

Campanularia crenata: Millard & Bouillon, 1973: 47, fig. 6B-F.

Diagnosis. Colony growing on weed, reaching 1,4 mm in height. Hydrothecal

pedicel deeply and spirally grooved, with one separate spherule of smaller

diameter at distal end, with thickened perisarc.

Hydrotheca deep-bell-shaped, 0,3-0,5 mm in depth and 0,18-0,4 mm in

maximum diameter, depth always greater than diameter, usually compressed,

perisarc often greatly thickened, especially at the narrow ends, but thinning

down at margin. Margin with 12-13 low, rounded teeth.

Gonotheca borne on hydrorhiza on short, smooth pedicel, strongly com-

pressed, truncated distally and with widest part at distal end, smooth or with

irregular outline; male containing one gonophore with four columns of sperma-

togenic cells; female containing two gonophores, one large and one small,

with eggs in longitudinal rows.

Variation. The spiral grooving on the pedicel usually extends throughout, but

occasionally there are smooth areas.

In the thicker hydrothecae marginal teeth may be absent. This appears to

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 205

Fig. 67.

Campanularia africana. A, colony with female gonophores, redrawn from Warren (1908, as

Campanularia tincta).

Campanularia hincksii. B—D, hydrothecae; E, gonotheca.

Campanularia laminacarpa. F-H, hydrothecae; J, male gonophore; K, female gonophore.

Scale in mm/10.

206 ANNALS OF THE SOUTH AFRICAN MUSEUM

be the result of damage and loss of the ‘thinned down’ edge bearing the teeth.

The type material had some hydrothecae without teeth.

The gonophore is reported to have a short free-living life as a eumedusa,

possessing four radial canals and eight statocysts, but with no marginal ten-

tacles or stomach (Hirohito).

Distribution outside South Africa. Atlantic (Sargasso Sea to Cape Verde),

Mediterranean, Seychelles, Australasia, Japan, Chile. Type locality: New

Zealand.

Distribution in South Africa. Mocgambique only, Inhaca to Inhambane, littoral

to 3 m. (For Campanularia ?crenata in Millard 1958, see C. delicata.) 26/32

(I), 24/35 (s)

Campanularia ?delicata (Trebilcock, 1928)

Fig. 68G—L

Orthopyxis delicata Trebilcock, 1928: 3, pl. 2 (fig. 1-1f). Ralph 1957: 837, 840, fig. 7a—d.

Campanularia ?crenata: Millard, 1958: 170, fig. 2A—C, E.

Campanularia delicata: Millard & Bouillon, 1973: 48, fig. 6G-M.

Diagnosis. Colony usually growing on weed, reaching 4,6 m in height. Hydro-

thecal pedicel annulated to a varying extent at base and distal end, but always

with one flattened spherule of smaller diameter at distal end.

Hydrotheca funnel-shaped, with straight or slightly curved sides widening

to margin, 0,3-0,6 mm in depth and 0,2-0,6 mm in marginal diameter, depth

usually more or less equal to diameter, circular in cross-section. Margin with

9-15 triangular teeth. Perisarc capable of great thickening to a level just below

the margin and excluding the marginal teeth.

Gonotheca borne on hydrorhiza on short, smooth pedicel; erect, circular

or very slightly compressed in section, deep-oval in side view with widest part

near centre.

Variation. The amount of annulation on the pedicel varies. At the base there

may be up to 11 annulations and at the distal end up to 15, the intervening

stretch being smooth or corrugated. Short pedicels are usually annulated

throughout.

The annular perisarcal thickening round the base of the hydrotheca may or

may not be separated from the thecal wall by a definite line.

Remarks. On the basis of Ralph’s work (1957) Millard’s material reported as

Campanularia ?crenata in 1958 has been transferred to C. delicata. The two

species are not easily distinguished and it may be necessary to unite them in the

future. C. delicata is characterized by a hydrotheca which is not compressed

and has deeper marginal teeth and by a gonotheca which is broadest near the

centre and is not or only very little compressed. The pedicel is also different,

with distinct but shallow annulations at the two ends instead of the deep spiral

grooving of C. crenata.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

207

SNe

Rope

Fig. 68.

Campanularia crenata. A—C, hydrothecae; D, t.s. hydrotheca; E, male gonophore; F, female

gonophore.

Campanularia ?delicata. G-J, hydrothecae (the centre one the most typical); K, t.s. hydrotheca;

L, male gonophores.

Scale in mm/10.

208 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. New Zealand, Australia, ?Sargasso Sea,

Seychelles. Type locality: Dunedin, New Zealand.

Distribution in South Africa. Mocgambique (Kosi Bay to Inhambane), littoral to

15 m. 27/32 (1), 26/32 (1, s), 25/32, 24/35 (s)

Campanularia hincksii Alder, 1856

Fig. 67B-E

Campanularia hincksii Alder, 1856: 360, pl. 13 (fig. 9). Hincks, 1868: 162, fig. 18, pl. 24 (fig. 3).

Millard, 1966a: 471, fig. 12A—D.

Diagnosis. Colony reaching a height of 8,4 mm. Hydrothecal pedicel not

annulated or corrugated, but with a single spherule at distal end.

Hydrotheca deep-campanulate, large, 0,9-1,6 mm in depth and 0,5-0,9

mm in marginal diameter, depth 14-2} times diameter, longitudinally striated

in distal part, polygonal in cross-section. Margin with 8-12 broad teeth which

are usually hollowed distally to form two points.

Female gonotheca borne on hydrorhiza, elongate-oval, with widest part

near base and narrowing slightly to truncated distal end, with about eight

rounded transverse annulations, containing fixed sporosacs.

Variation. The hydrothecal pedicel occasionally shows irregularities such as

cross-striations, but these appear to be due to regeneration after injury. Alder

shows ‘two or three slight spiral twists’ at the base of the pedicel in the type

material, but these have not been observed in South Africa.

The marginal teeth are occasionally truncated distally, and this appears to

be the result of wearing down of the two points. The longitudinal striations on

the hydrotheca start at the angles between the marginal teeth and are continued

to a varying degree down its length. In some cases they reach to the base, and

in others they peter out about halfway.

Male gonothecae have not been seen in South Africa and there is some

doubt as to their structure. Stechow (19195) describes smooth male gonothecae

which widen distally in C. alta, thought by Broch (1933) to be a synonym for

C. hincksii.

Distribution. Cosmopolitan. Type locality: Northumberland, U.K.

Distribution in South Africa. Off East London, in 86-210 m. Rare. 32/28 (s),

32/29 (d)

Campanularia integra MacGillivray, 1842

Fig. 69

Campanularia integra MacGillivray, 1842: 465. Hincks, 1868: 163, pl. 31 (fig. 1). Broch,

1909: 185, fig. 40. Millard, 1966a: 472, fig. 13A—D.

Campanularia caliculata Hincks, 1853: 178, pl. 5 (fig. B). Hincks, 1868: 164, pl. 31 (fig. 2).

Warren, 1908: 338, fig. 19.

Campanularia compressa Clarke, 1876: 214, pl. 8 (figs 5-6).

ae mira Hartlaub, 1897: 504, pl. 22 (figs 5, 8-10). Russell, 1953: 303, figs 186-188,

pl. 19 (fig. 1).

Agastra rubra Behner, 1914: 393, figs 8-10, pl. 7 (fig. 6). Kramp, 1959: 146, fig. 183.

?Campanularia gracilis Stechow, 1925a: 423, fig. 6.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 209

Diagnosis. Colony growing on weeds, other hydroids and the crab Dehaanius

dentatus, reaching 4 mm in height. Hydrorhiza reticulate, often with a flat

lateral flange of perisarc. Hydrothecal pedicel spirally annulated, roughly

corrugated or quite smooth, but always with one spherule of smaller diameter

at distal end.

Hydrotheca campanulate, sometimes with slightly everted margin; 0,2-

0,6 mm in depth and 0,2-0,5 mm in marginal diameter; in cross-section fairly

thin and circular to grossly thickened, especially on two opposite sides, and

then oval in cross-section and bilaterally symmetrical. Margin untoothed.

Hydranth with 25-30 tentacles.

Gonotheca borne on hydrorhiza, generally laterally compressed, but some-

times round in cross-section; generally smooth and oval to pear-shaped in

broad view, but often irregularly corrugated; with truncated distal end and wide

operculate aperture; containing one to three (usually two: one large and one

small) eumedusoid gonophores. Gonophore with four pigmented radial canals

bearing irregular branching diverticula along entire length and rarely with four

marginal bulbs and eight statocysts. Male with four band-like gonads extending

full length of radial canals. Female with 30-40 large eggs arranged roughly in

eight longitudinal rows between the diverticula of the radial canals.

Variation and remarks. All South African material appears to belong to one very

variable species, here taken to be C. integra. Attempts to separate two species

on the trophosome have been unsuccessful. Some colonies have spirally annu-

lated pedicels throughout, others have smooth pedicels and others have a

mixture of all types ranging from strongly annulated to quite smooth.

The strength of the perisarc is equally variable; in some colonies it is thin

throughout with hydrothecae which are completely radially symmetrical. In

others the lateral flanges of the hydrorhiza are so extensive that they fuse with

one another to form a mat and the hydrothecae are grossly thickened. The

thickening of the hydrotheca usually terminates just below the margin, and is

always more strongly developed on two opposite sides imparting a bilateral

symmetry and oval cross-section. Thickened colonies of this sort invariably

have a few thin-walled hydrothecae as well.

The gonotheca is similarly variable. Though generally compressed and

irregularly oval in broad view, elongate rounded forms may occur in the same

colony. Many irregularities in shape occur, but never is there a spiral annula-

tion so marked as that illustrated by Hincks (1868) for C. integra.

Medusae of this genus (Agastra) have not been recorded from the plankton

in South Africa and living material has not been seen to release active medusae,

although this may possibly occur under certain conditions. In the laboratory

the gonophores release their sexual products while still within the gonothecae.

In partly spent gonophores the medusoid structure can sometimes be seen and is

best observed by dissecting the gonophore out of the gonotheca. Specimens

with four perradial marginal bulbs bearing vestigial marginal tentacles up to

210 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 69.

Campanularia integra. A-C, hydrothecae with smooth stems, in narrow view, broad view and

t.s. respectively; D and E, hydrotheca with annulated stem in t.s. and broad view respec-

tively; FF, hydrotheca with thin perisarc; G, female gonophore with round section;

H, female gonophore with flat section; J-L, female gonophores dissected from gonothecae,

J immature with radial canals containing pigment, K mature, L partly spent and showing

medusoid structures; M, male gonophore.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 211

0,06 mm in length and with eight adradial statocysts have been observed.

When the gonophore is full and mature the marginal structures are usually not

visible and possibly not always present. The radial canals are often clearly

demarcated by the presence of a brown pigment within them.

I have followed Broch (1909, 1918) in synonymizing C. integra and

C. compressa. Both species are known to release degenerate short-lived medusae

at certain seasons. The medusa of C. integra is Agastra mira, which is said to be

distinguished by radial canals with a few diverticuli restricted to the central part

and many small irregularly arranged eggs. The medusa of C. compressa 1s

Agastra rubra, distinguished by radial canals bearing diverticuli along their

entire length and fewer but larger eggs in longitudinal rows. Further observa-

tion is needed to determine whether or not these differences are due to seasonal

variation or sex; if valid the South African material would appear to be closer to

C. compressa.

Distribution. Cosmopolitan. Type locality: Don Mouth, U.K.

Distribution in South Africa. Northern South West Africa and Table Bay to

Mocambique, littoral to 27 m, with a dubious record (Stechow) from 100 m,

very abundant on weed in certain areas. 20/13 (1), 33/18 (1), 34/18 (, s), 34/22

(1, s), 234/23 (d), 33/25 (s), 33/27 (s), 30/30 (1), 29/31 (1, s), 26/32 (1, s)

_ Campanularia laminacarpa Millard, 1966

Fig. 67F-K

Campanularia laminacarpa Millard, 1966a: 472, fig. 12E—-K.

Diagnosis. Colony epizootic on Thyroscyphus aequalis, reaching 2,0 mm in

height. Hydrothecal pedicel smooth or corrugated, with one spherule of smaller

diameter at distal end.

Hydrotheca deep-campanulate, with almost parallel sides, 0,4-0,7 mm in

depth and 0,2-0,3 mm in marginal diameter, depth 14-24 times diameter.

Margin with 10-14 rounded teeth separated by rounded bays of approximately

the same size.

Gonotheca borne on hydrorhiza, large, usually smooth, flattened, with

truncated distal end and wide, operculate, terminal aperture. Male and female

similar, but on different colonies. Female containing a single heteromedusoid

gonophore with numerous small eggs; male containing a single eumedusoid

gonophore with spermatogenic cells arranged in four longitudinal bands and

with indications of four radial canals.

Variation. The gonothecae may have certain irregularities in the contours, but

are always compressed.

Remarks. Sterile colonies of this species cannot be distinguished from C. afri-

cana. Fertile specimens of C. laminacarpa have been found only on Thyroscy-

phus, and the species may be specific to this host. Infertile records from other

212 ANNALS OF THE SOUTH AFRICAN MUSEUM

hosts have been omitted in the distribution below, and infertile records from

Thyroscyphus are given with a query.

Distribution. Endemic to South Africa.

Distribution in South Africa. Certain records: Agulhas Bank from Cape Agulhas

to East London; possibly extending farther west to False Bay and farther north

to Mocambique; 4-110 m and possibly 2-219 m. Type locality: Agulhas Bank,

34°49 'S/20°21,5’E, depth about 91 m. 234/18 (s), 34/20 (s), ?34/21 (s), 35/21

(d), 33/25 (s), ?34/25.(s), 33/26 (Ss), 33/27 (S);, 232/28 (Ss), 229/31 Gs 225/326)

224/35 (s)

Campanularia morgansi Millard, 1957

Fig. 71C-E

Campanularia morgansi Millard, 1957: 195, fig. 6.

Diagnosis. Colony generally epizootic on other hydroids, also found on Pyura

and Perna perna, reaching 2,9 mm in height. Hydrothecal pedicel roughly

corrugated in basal region, with one somewhat flattened spherule at distal end.

Hydrotheca deep-campanulate, with a distinct raised rim just below margin,

0,4-0,7 mm in depth and 0,2-0,4 mm in maximum diameter, depth 13-3 times

diameter. Margin with 8-13 usually bluntly rounded teeth separated by rounded

bays. Hydranth with about 16 tentacles.

Gonotheca borne on hydrorhiza on short annulated pedicel, spindle-

shaped, deeply annulated with 5-9 annulations over ? length, distal region

smooth, with terminal aperture. Male and female similar, containing a single

styloid gonophore, which in the female bears numerous eggs which develop

into planulae in situ.

Variation. The length of the hydrothecal pedicel is variable, and the terminal

spherule is usually, but not always, of smaller diameter than the rest. The raised

rim of the hydrotheca is always distinct and may be strongly thickened. The

marginal teeth are usually rounded, but may also be sharply pointed.

Distribution outside South Africa. Madagascar.

Distribution in South Africa. Lambert’s Bay to Inhaca, in 0-210 m. Type locality:

False Bay, 73 m. 32/18 (s), 33/18 (s), 34/18 (s, d), 34/21 (s), 34/22 (s), 35/22 (d),

33/25 (s), 33/27 (s), 32/28 (s), 32/29 (d), 29/31 (s, d), 28/32 (s), 25/32 (s)

Campanularia pecten Gow & Millard, 1975

Fig. 70A-F

Campanularia ?mollis: Millard, 1966a: 476, fig. 13E-J.

Campanularia pecten Gow & Millard, 1975: 1, fig. 1.

Diagnosis. Colony growing on weeds, reaching 2,7 mm in height. Hydrothecal

pedicel smooth, with thickened perisarc and one spherule of smaller diameter

at distal end, often with regeneration nodes.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 213

Hydrotheca deep-campanulate, 0,5-0,8 mm in depth and 0,2-0,4 mm in

marginal diameter. Margin with 7-10 (usually 9) teeth with bluntly rounded

apices and usually narrower than the bays between them. Perisarc capable of

great thickening, particularly at two opposite sides resulting in an oval cross-

section.

Gonotheca borne on hydrorhiza on short, smooth pedicel, scallop-shaped

and opening like a bivalve shell; lower valve flattened, upper valve thicker

and convex often with concentric ridges on outer surface, containing a single

eumedusoid gonophore. Eumedusoid released for a short free-living life, only

male known, with four radial canals with gonads distributed along their length,

eight statocysts, but no marginal tentacles or hypostome.

Remarks. I have included in this species the infertile material previously ascribed

to C. ?mollis. In this colony the hydrothecae are a little deeper than in the holo-

type and the marginal teeth are sometimes bifurcated at the tip.

Distribution. Endemic to South Africa.

Distribution in South Africa. Cape Peninsula, east and west coasts, littoral. Type

locality: St. James. 33/18 (1), 34/18 (1)

Campanularia roberti Gow & Millard, 1975

Fig. 70G-J

Campanularia roberti Gow & Millard, 1975: 3, fig. 2.

Diagnosis. Colony growing on weeds, reaching 3,5 mm in height. Hydrothecal

pedicel smooth, with thickened perisarc and one spherule of smaller diameter at

distal end, often with regeneration nodes.

Hydrotheca deep-campanulate, 0,6-0,9 mm in depth and 0,3-0,6 mm in

marginal diameter. Margin with 9-11 triangular teeth with bluntly rounded

apices. Perisarc capable of great thickening, particularly at two opposite sides

and more on one side than the other resulting in an asymmetrical shape and an

oval cross-section.

Gonotheca borne on hydrorhiza on short, smooth pedicel, scallop-shaped

and opening like a bivalve shell, recumbent, lower valve flattened, upper valve

thicker and convex with concentric ridges on outer surface, containing a single

gonophore in the form of a fixed sporosac. Gonophore (only female known)

with four branching radial canals and over 30 eggs between the diverticuli,

with no other medusoid characters. Eggs developing into planuli in situ.

Distribution. Endemic to South Africa.

Distribution in South Africa. Cape Peninsula, east and west coats, littoral. Type

locality: Partridge Point. 33/18 (1), 34/18 (1)

Genus Clytia Lamouroux, 1812

Syn. Phialidium Leuckart, 1856.

Diagnosis. Colony usually minute and stolonial, but sometimes branching in

214 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 70.

Campanularia pecten. A and B, hydrothecae; C, spent gonotheca in side view; D, eumedusa

in ventral view, showing, from the centre outwards: opening to subumbrellar cavity,

exumbrellar aperture, ring of statocysts, gonads on radial canals; E and F, gonothecae,

F containing a male gonophore.

Campanularia roberti. G and H, gonothecae, H containing a female gonophore and showing

pigmented radial canals; J, hydrothecae.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA PANES

the form of a sympodium. Hydrotheca deep, campanulate or funnel-shaped,

radially symmetrical, usually with toothed margin. Diaphragm present, of

variable thickness but always distinctly demarcated from hydrothecal wall.

Gonotheca producing free medusae. Medusa hemispherical, with normal velum,

hollow marginal tentacles and numerous statocysts.

Type species: Medusa hemisphaerica Linnaeus, 1867

= Sertularia volubilis Ellis & Solander, 1786 (non Linnaeus, 1758)

KEY TO SPECIES

1. Hydrotheca without marginal teeth ae &. ue rr, C. hummelincki

— Hydrotheca with teeth i - te a ce ns Bee a7 aw ee

2. Marginal teeth bilobed a oe a ee ae 3:3 fe C. paulensis

— Marginal teeth single ok ; a ‘eee:

3. Hydrotheca longitudinally striated, diet ett nected on inner cane C. gravieri

— Hydrotheca not striated, marginal teeth not keeled de ae ie Bie fo pee

4. Pedicel corrugated at base, and with one spherule at distal end belo hydrotheca

C. paradoxa

— Pedicel closely annulated at base and at distal end As , Re +

5. Hydrotheca with depth approximately equal to diameter; ae eat heath low and

rounded a C. latitheca

Hydrotheca always deeper than wide: marginal teeth triangular, usually sharp we | O

6. Hydrotheca not more than 1 mm deep, depth about 13-24 times marginal diameter,

mever over 3 times .. : ee .. C. hemisphaerica

— Hydrotheca over 1 mm deep, aout anh eS Afanmneiee re a .. C. warreni

Clytia gravieri (Billard, 1904)

Fig. 71F-H

Campanularia gravieri Billard, 19046: 482, fig. 1.

Obelia striata Clarke, 1907: 9, pls 6-7.

Clytia gravieri: Billard, 1938: 429, figs 1-3. Millard & Bouillon, 1973: 51, fig. 7ZE-G.

Clytia serrata Millard, 1958: 173, fig. 3C, H.

Campanularia (Clytia) gravieri: Vervoort, 1967: 50, fig. 16.

Diagnosis. Colony growing on pteropod shells, weed and other hydroids,

reaching 9 mm in height. Hydrothecal pedicel unbranched and bearing one

hydrotheca only, or branching sympodially to give rise to several alternate

hydrothecae, closely annulated at base, on origin of branches and at distal

end.

Hydrotheca very delicate, deep-campanulate, expanding to margin or

with almost parallel sides, longitudinally striated in distal region for about

one-third of length, 0,4-1,1 mm in depth and 0,12-0,5 mm in marginal diameter,

depth two to three times diameter. Margin with 8-13 sharp, pointed teeth which

correspond to the striations and project inwards as longitudinal ridges, giving

to the cross-section an undulating outline. Diaphragm distinctly demarcated,

separating off a deep basal chamber.

Gonothecae borne on hydrorhiza or thecal pedicel, elongated pear-shaped,

reaching 0,8 mm in length and 0,3 mm in maximum diameter, smooth, truncated

distally, containing a string of medusa-buds. Pedicel short, annulated.

216 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig: 71

Clytia latitheca. A, branching stems; B, hydrotheca.

Campanularia morgansi. C and D, hydrothecae; E, female gonophore.

Clytia gravieri. F, stem; G, hydrotheca; H, gonothecae with medusa-buds.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA GALS |

Medusa deep and with four marginal tentacles at liberation, adult medusa

unknown.

Variation. This is one of the few species of Clytia in which the pedicel may

branch repeatedly producing upright stems superficially very like those of

Obelia. The hydrotheca is extremely variable in size.

Distribution outside South Africa. Tropical and subtropical regions of Atlantic,

Indian and Pacific Oceans. Type locality: off Djibouti in the Gulf of Aden.

Distribution in South Africa. On the pteropod Hyaloea (Diacria) trispinosa: west

coast as far south as 31°S, and south-east coast between 24°E and 30°50’S.

On hydroids and other substrata: Port Elizabeth to Mocgambique, 0-110 m.

a/250 (a), 29/31 (Ss), 26/32 (1), 25/32, 23/35 (Ss), 21/35. (Kramp’s records on

pteropods in 1921 not recorded in detail).

Clytia hemisphaerica (Linnaeus, 1767)

Fig. 72A—D

Medusa hemisphaerica Linnaeus, 1767: 1098.

Laomedea gracilis M. Sars, 1851: 138.

Clytia gracilis: Millard, 1957: 196. Millard, 1958: 172, fig. 3B, E, G.

Clytia johnstoni: Ralph, 1957: 820, 823, figs 1h—u, 2, 3a-f. Millard, 1958: 172, fig. 3A, D, F.

Phialidium hemisphaericum: Russell, 1953: 285, figs 172-179, pl. 16 (fig. 1), pl. 17 (fig. 6).

Clytia hemispherica: Rees & Thursfield, 1965: 95.

Clytia hemisphaerica: Millard, 1966a: 478, fig. 14A—F. Leloup, 1974: 14.

Laomedea (Phialidium) pelagica: Vervoort, 1968: 15, fig. 5.

Diagnosis. Colony generally growing on weeds or other hydroids. Hydrothecal

pedicel closely annulated at base and distal end, usually unbranched but some-

times branching sympodially once or twice. Colony reaching a maximum height

of 10 mm.

Hydrotheca deep-campanulate, expanding to margin, 0,3-1,0 mm in depth

and 0,13-0,6 mm in marginal diameter, depth usually 14-24 times diameter.

Margin with 7-15 teeth, which are usually sharply pointed. Diaphragm distinctly

demarcated from thecal wall, separating off a bell-shaped basal chamber.

Gonotheca borne on hydrorhiza or thecal pedicel, elongated, usually

constricted just below truncated distal end, generally smooth but sometimes

annulated, containing about four medusa-buds.

Medusa at liberation deep bell-shaped, with four marginal tentacles. Adult

medusa (not recorded from South Africa) hemispherical, reaching 20 mm in

diameter, with numerous statocysts and up to 32 marginal tentacles.

Variation. When branching occurs the secondary pedicels immediately bend

distally so that their axes are almost parallel to the primary one. The amount of

annulation on the pedicel varies; most have a smooth area in the centre, but

some are annulated throughout and some have scattered patches of annulation.

The hydrotheca is fairly constant in shape though the size is variable. In

general larger hydrothecae occur on the west and south coasts and smaller

218 ANNALS OF THE SOUTH AFRICAN MUSEUM

ones on the east coast. The marginal teeth vary in number and shape. In this

country they are always acute, covering a smaller area than the bays between

them, but the points may be sharp or bluntly rounded and are very often

asymmetrical, leaning to one side. The diaphragm varies in thickness but cannot

be confused with the annular thecal thickening of Campanularia.

Gonothecae are generally smooth, of the ‘C. gracilis’ form, but sometimes

have a few irregular corrugations, and are sometimes completely annulated

as in the ‘C. johnstoni’ form. The annulated gonothecae may be deep with a

wide truncated distal end, or shorter and more nearly oval with a narrower

aperture.

Remarks. Ralph (1957) showed that the gonotheca of C. johnstoni (Alder)

varies from fully annulated to smooth. Thus C. johnstoni becomes a synonym of

C. gracilis (M. Sars) = C. pelagica (van Breemen) = C. hemisphaerica. It may

be noted, however, that in South Africa the ‘johnstoni’ form with fully annulated

gonothecae does not occur south of Inhaca, and that at no time have fully

annulated and smooth gonothecae been found in the same colony.

Distribution. Cosmopolitan. Type locality: “Oceano Belgico’.

Distribution in South Africa. Northern South West Africa to Mocambique.

Common practically all round the coast, though often overlooked because of

the small size, littoral to 150 m. [18/12 (1),] 33/18 C, s), 34/18 (s), 35/19 (s),

35/20 (d), 34/21 (s), 35/21 (d), 34/22 (s, d), 34/23 (s, d), 34/24 (d), 33/25 (s),

34/25 (s), 33/26 (s), 33/27 (s), 32/28 (s), 31/30 (1), 31/29 (s), 29/31 (, s, h), 28/32

(Ciseud) 26/525 (s)he) 82525) S 5 (I) et Ss

Clytia hummelincki (Leloup, 1935)

Fig. 72F—H

Laomedea hummelincki Leloup, 1935: 19, fig. 7.

Clytia hummelincki: Millard, 1966a: 480, fig. 14G-—L.

Diagnosis. Colony growing on the stalked barnacle, Lepas, reaching 4,9 mm in

height. Hydrothecal pedicel unbranched, closely annulated at base and some-

times at scattered intervals above this, with a single flattened segment at distal

end.

Hydrotheca funnel-shaped, with straight sides expanding evenly to margin,

0,3—-0,4 mm in depth and 0,2-0,4 mm in marginal diameter; depth approximately

equal to diameter. Margin untoothed. Diaphragm delicate, usually oblique,

separating off a funnel-shaped basal chamber.

Gonotheca borne on hydrorhiza, elongated, smooth, truncated distally,

containing one or two medusa-buds.

Medusa-bud deep, with four radial canals and four marginal bulbs. Adult

medusa unknown.

Distribution outside South Africa. Isle Bonaire, West Indies, on coral (type

locality).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 219

Fig. 72.

Clytia hemisphaerica. A, two hydrothecae and a gonotheca; B, hydrotheca; C, gonotheca of

‘gracilis’ form; D, gonotheca of ‘johnstoni’ form.

Clytia paradoxa. E, hydrothecae, redrawn from Stechow (1925a, as Eucalix paradoxus).

Clytia hummelincki. F, hydrothecae and gonotheca; G and H, gonothecae.

Scale in mm/10.

220 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. One record only, from Agulhas Bank, on buoy.

34/25 (h)

Clytia latitheca Millard & Bouillon, 1973

Fig. 71A-B

Clytia latitheca Millard & Bouillon, 1973: 55, fig. 7H-L.

Diagnosis. Hydrothecal pedicel either unbranched and bearing a single terminal

hydrotheca, or branching sympodially to form a geniculate erect stem reaching

a maximum height of 6 mm. Stem closely annulated at base, distal end, on

origin of branches and occasionally at other irregular intervals.

Hydrotheca obconical, with straight walls, 0,3-0,6 mm in depth and 0,4—

0,6 mm in marginal diameter, depth approximately equal to diameter. Margin

with 13-14 low rounded teeth. Diaphragm thin, distinct from thecal wall.

Basal chamber deep. Hydranth with about 28 tentacles.

Gonotheca (not reported from South Africa) borne on stem, smooth,

elongated, widening evenly to truncated distal end, containing a string of 3-6

medusa-buds, which are deep and have at least four marginal tentacles at

liberation. Adult medusa unknown.

Variation. This species is very variable in form and is one of the few which may

form an erect branching stem. The branching is very obviously sympodial and

often two branches arise in close succession giving a subdichotomous effect.

Colonies from South Africa are small, but taller ones (reaching 15 mm) occur in

the Seychelles and are occasionally lightly fascicled at the base. The hydrotheca

is variable in size but very characteristic in shape.

Distribution outside South Africa. Seychelles only; type locality: Praslin.

Distribution in South Africa. Inhaca in Mocambique only. 25/32

Clytia paradoxa (Stechow, 1923)

Fig. 72E

Eucalix paradoxus Stechow, 1923b: 104. Stechow, 1925a: 433, fig. 11.

Diagnosis. Colony growing on other hydroids. Hydrothecal pedicel unbranched,

corrugated in basal region, forming one spherule of lesser diameter at distal

end.

Hydrotheca deep-campanulate, with a distinct raised rim just below margin,

0,4 mm in depth and 0,18 mm in marginal diameter, depth about 2% times

diameter. Margin with 9-10 triangular teeth separated by rounded bays.

Diaphragm distinctly demarcated, thin, separating off a campanulate basal

chamber.

Gonothecae unknown.

Remarks. This species is included in the genus Clytia on the basis of the

diaphragm. For the rest its structure is reminiscent of Campanularia, particularly

C. morgansi. It has not been rediscovered since Stechow’s report.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA pips)

Distribution. Endemic to South Africa.

Distribution in South Africa. South coast from 20 to 25°E, in 100 m. Type

locality: 35°27 ‘S/20°56’E, 100 m. 35/20 (d), 34/24 (d)

Clytia paulensis (Vanhoffen, 1910)

Fig. 73A—D

Campanularia paulensis Vanh6ffen, 1910: 298, fig. 19.

Clytia paulensis: Stechow, 1923c: 110, fig. N. Millard, 1966a: 481, fig. 15.

?Clytia ulvae Stechow, 1919b: 47, fig. N. Stechow, 1925a: 428.

Diagnosis. Colony usually growing on other hydroids, reaching 3 mm in height.

Hydrothecal pedicel unbranched or sparsely branched, closely annulated at

base and distal end and sometimes at scattered intervals between.

Hydrotheca deep-campanulate, with almost parallel sides, 0,3-0,7 mm in

depth and 0,13-0,3 mm in marginal diameter; depth two to three times diameter.

Margin with 7-11 bilobed teeth, points narrow and bluntly rounded. Diaphragm

very delicate, separating off a campanulate basal chamber.

Gonotheca borne on hydrorhiza, elongated, smooth, truncated distally

with annulated pedicel, containing one to three medusa-buds.

Medusa-bud with four marginal tentacles. Adult medusa unknown.

Variation. The double marginal teeth are characteristic of the species and

usually very distinct. However, the bays between members of a pair are some-

times nearly as deep as the bays between pairs and the double nature of the

teeth is not so easily seen. The single teeth thus vary from 4 to 3-the length of

the double teeth. Since the margin of the hydrotheca is bowed out between

the teeth the distal end of the hydrotheca often appears to have longitudinal

striations, especially in mounted preparations where the side-walls tend to

crumple.

Distribution outside South Africa. North Atlantic, Mediterranean, California,

Indian Ocean, Antarctic. Type locality: St. Paul, southern Indian Ocean.

Distribution in South Africa. South and east coasts, from Cape Infanta to Inhaca,

0-138 m. 34/20 (s), 34/22 (s), 34/23 (s), 34/24 (d), 33/25 (s), 34/25 (s), 32/28 (s),

29/31 (s, d), 28/32 (s), 26/32 (s)

Clytia warreni Stechow, 1919

Fig. 73E-F

Clytia elongata Warren, 1908: 339, fig. 20.

Clytia warreni Stechow, 1919b: 48.

Diagnosis. Colony epizootic on Thyroscyphus. Hydrothecal pedicel unbranched,

1,3-3,2 mm in length, closely annulated at base and distal end, the terminal

segment being smaller than the rest.

Hydrotheca obconical, expanding to margin, 1,1-1,3 mm in depth and

0,3-0,4 mm in marginal diameter, depth 3-4 times diameter. Margin with about

222 ANNALS OF THE SOUTH AFRICAN MUSEUM

ela

by,

Bie: 73:

Clytia paulensis. A-C, hydrothecae; D, gonotheca.

Clytia warreni. E, two gonothecae and a hydrotheca, redrawn from Warren (1908, as

C. elongata); F, hydrotheca, drawn from Warren’s holotype borrowed from the Natal

Museum.

Eulaomedea calceolifera. G, stem; H, hydrotheca and hydranth; J, male gonophore;

K, female gonophore.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 223

12 sharp teeth. Diaphragm distinct, separating off a deep-campanulate basal

chamber.

Gonotheca borne on hydrorhiza, elongated and narrowing slightly to

truncated distal end, smooth, containing three or four medusa-buds.

Adult medusa unknown.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only record: Algoa Bay in 73 m.

33/25 (s)

Genus Eulaomedea Broch, 1909

Diagnosis. An upright stem present, which may be fascicled or unfascicled,

branched or unbranched. Stem divided into regular internodes bearing alternate

hydrothecae. Hydrotheca campanulate, radially symmetrical. Diaphragm

distinctly demarcated from thecal wall. Gonothecae containing gonophores in

the form of fixed sporosacs or degenerate medusae which release their sexual

products within the gonothecae.

Type species: Laomedea flexuosa Alder, 1856.

One species only from South Africa.

Eulaomedea calceolifera (Hincks, 1871)

Fig. 73G—-K

Campanularia calceolifera Hincks, 1871: 78, pl. 6. Nutting, 1915: 49, pl. 9 (figs 2-4).

Laomedea angulata: Millard, 1959b: 248.

Diagnosis. Stem unfascicled, flexuous, unbranched or weakly branched, reaching

23 mm in height, geniculate, bearing alternate hydrothecae. Internodes annu-

lated on proximal end, slender, each with a distal apophysis alternately on the

right and the left, which bears a hydrotheca and/or a branch. Branches similar

to stem. Hydrothecal pedicel annulated throughout or with a smooth area in

centre, generally longer than hydrotheca.

Hydrotheca campanulate, 0,4-0,6 mm in depth and 0,2—0,4 mm in marginal

diameter. Margin untoothed, usually slightly everted. Diaphragm straight.

Gonothecae arising in axils of thecal pedicels or branches, with annulated

pedicels, male and female on separate colonies. Female gonotheca smooth,

slipper-shaped, widening gradually from pedicel to distal end, which is

obliquely truncated, the abcauline edge curling over to form a tube directed

distally into the cavity; containing about 10 heteromedusoid gonophores, each

with one egg; eggs developing into planulae within the gonotheca. Male gono-

theca smooth, elongated, spindle-shaped, with small inturned terminal aperture,

containing about seven styloid gonophores in one row, one upon the other.

Distribution outside South Africa. North Atlantic from coast of America to

Europe, Mediterranean. Type locality: Salcombe Bay, U.K.

224 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. In Cape Town docks on ships’ hulls. An infertile

record from Simon’s Bay, 70 m (Stechow 1925a). 33/18 (h), 34/18 (s)

Genus Gonothyraea Allman, 1864

Diagnosis. An upright, branching stem present, which may be fascicled or

unfascicled. Stem divided into regular internodes bearing alternate hydrothecae.

Hydrotheca campanulate, radially symmetrical. Diaphragm distinctly demar-

cated from thecal wall. Gonophores forming degenerate medusae (meconidia)

which are extruded from the gonothecae into acrocysts, but remain attached and

release the sexual products in position. Meconidium with marginal tentacles,

but no mouth or sense organs.

Type species: Laomedea loveni Allman, 1859.

One species only from South Africa.

Gonothyraea loveni (Allman, 1859)

Fig. 74A—F

Laomedea Loveni Allman, 1859: 138.

Gonothyraea Lovéni: Hincks, 1868: 180, pl. 25 (fig. 2). Allman, 1871: 55, fig. 28.

Laomedea lovéni: Millard, 19595: 249.

Diagnosis. Stem unfascicled, flexuous, richly branched, reaching 40 mm in

height, straight or weakly geniculate, bearing alternate hydrothecae and

branches. Internodes annulated on proximal end, slender, each with a distal

apophysis alternately on the right and the left, which bears a hydrotheca and/or

a branch. Branches similar to stem. Hydrothecal pedicel annulated throughout,

shorter than hydrotheca.

Hydrotheca deep-campanulate, very delicate, 0,4-0,6 mm in depth and

0,18-0,4 mm in marginal diameter. Margin with about 10 truncated teeth

separated by rounded bays. Diaphragm thin, straight. Hydranth with 19-33

tentacles held alternately elevated and depressed.

Gonothecae arising in axils of thecal pedicels or branches singly or in pairs,

smooth, elongated, widening gradually to truncated distal end, containing 4-5

(rarely up to 8) eumedusoid gonophores in a single row, one upon the other.

Gonophores extruded through aperture as meconidia but remaining in cyto-

plasmic continuity with blastostyle. Meconidium with four radial canals, a

circular canal and a ring of small marginal tentacles, but no mouth or sense

organs. Male with about five marginal tentacles and releasing the sexual products

in situ. Female with about eight marginal tentacles and 3-5 eggs, which are

fertilized and develop into planulae in situ.

Colour: coenosare creamy white throughout, tentacles transparent.

Distribution outside South Africa. Arctic and North Atlantic, from America

to Europe, Morocco, Mediterranean, New Zealand, Tasmania. Probably spread

to the southern hemisphere by ships. Type locality: Great Britain.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 225

. rH it

\\ ay | :

Cece di We 77

Ue atin 7

"ae

id ak

MTT ATTICS

Fig. 74.

Gonothyraea loveni. A, stem with female gonophores; B, hydrotheca; C and D, female and

male gonophores releasing meconidia; E, female meconidium with planulae; F, empty

male meconidium.

Obelia sp., medusae. G, newly liberated; H, in a typical swimming position; J, the largest

specimen seen; K, edge of bell showing tentacle roots, circular canal and statocyst.

Scale in mm/10.

226 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. In Cape Town docks only, on ships’ hulls,

experimental submerged plates, pylons and cables. 33/18 (s, h)

Genus Obelia Péron & Lesueur, 1809

Diagnosis. An upright stem present, which may be fascicled or unfascicled,

branched or unbranched. Stem divided into regular internodes bearing alternate

hydrothecae. Hydrotheca campanulate, radially symmetrical, with toothed or

untoothed margin. Diaphragm distinctly demarcated from thecal wall. Gono-

thecae releasing free medusae. Medusa shallow and saucer-shaped, with rudi-

mentary velum, numerous solid marginal tentacles and eight statocysts, each

with one concretion.

Type species: Sertularia geniculata Linnaeus, 1758.

Remarks on medusae (Fig. 74G—-K). The medusae of the various species of

Obelia cannot as yet be distinguished from one another. Obelia medusae occur

commonly in the plankton round the South African coast, and are easily recog-

nized by their characteristic rapid pulsation and shallow bell, which often

‘turns inside out’ during swimming. The smallest ones observed, which have

presumably just escaped from the gonothecae, are | mm in diameter and have 16

marginal tentacles. The largest ones are 4 mm in diameter and have about 140

marginal tentacles. The gonads are round and borne on the centre of the radial

canals.

Colour: gonads and tentacle-bases straw-coloured, the rest transparent.

KEY TO SPECIES

1. Hydrothecal margin toothed a: ate es fs os ee is eg 2

— Hydrothecal margin untoothed a s oe wa ee one A sa) Utes

2. Marginal teeth bilobed ae a aN Af a Pe O. bicuspidata

— Marginal teeth single, low and rounded a eng , Aye O. dichotoma

3. Stem strongly geniculate, internodes with niononneed eneareal thickenings on

alternate sides O. geniculata

— Stem seldom obviously geniculate, internodes without perisarcall thicken: O. dichotoma

Obelia bicuspidata Clarke, 1875

Fig. 75C-E

Obelia bicuspidata Clarke, 1875: 58, pl. 9 (fig. 1). Millard, 19595: 249. Mammen, 1965a:

11, figs 37-38.

Laomedea bicuspidata: Vervoort, 1946a: 298, fig. 132. Vervoort, 1968: 19, fig. 7.

Diagnosis. Stem fascicled or unfascicled, branched or unbranched, reaching

9 mm in height, geniculate in younger regions only, bearing alternate hydro-

thecae. Internodes slender, with thin perisarc, with three or more close annula-

tions at proximal end, bearing a hydrotheca on a short apophysis at distal end.

Branches when present, arising next to a hydrotheca, similar to stem. Hydro-

thecal pedicels of variable length, annulated throughout or with smooth area in

centre.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 227

Hydrotheca deep-campanulate, polygonal in section, 0,3-1,1 mm in depth

and 0,18-0,5 mm in marginal diameter, depth 13-34 times diameter. Margin

with 8-12 teeth, each of which is bilobed, terminating in two slender, keeled

spines. Diaphragm delicate, straight or slightly oblique.

Gonothecae arising in axils of hydrothecal pedicels, smooth, elongated,

widening to broad distal end, with terminal aperture but no neck. Pedicel

annulated.

Variation. The known South African material is sparsely branched with unfas-

cicled stems. More luxurious material might be expected to have fascicled stems

and more prolific branching. Variation occurs in the origin of the branches and

hydrothecae, and the latter may arise in pairs.

The size of the bays between members of a pair of marginal teeth varies,

and may be almost as deep as the bays between the double teeth or quite shallow.

Some hydrothecae are obviously longitudinally striated, others not at all.

Distribution. Cosmopolitan in tropical and temperate waters. Type locality:

Long Island Sound, 5-9 m.

Distribution in South Africa. Table Bay, and the east coast from Durban to

Inhaca; on ships’ hulls, hermit shells and weed. 33/18 (h), 29/31 (s), 28/32 (s),

2/32 S), 25/32

Obelia dichotoma (Linnaeus, 1758)

Fig. 75F-J

Sertularia dichotoma Linnaeus, 1758: 812.

Obelia dichotoma: Hincks, 1868: 156, pl. 28 (fig. la—d). Millard, 1966a: 483.

Obelia dubia: Vanhoffen, 1910: 307, fig. 27.

Laomedea dichotoma: Vervoort, 1946a: 292, fig. 128.

Diagnosis. Stem unfascicled, branched or unbranched, reaching 90 mm in height

but usually much less, straight or geniculate, bearing alternate hydrothecae.

Internodes annulated on proximal end, slender, bearing a hydrotheca on a short

apophysis at distal end. Branches alternate or subdichotomous, usually arising

from the same apophysis as the hydrotheca, similar to stem in structure. Hydro-

thecal pedicels annulated throughout or with a smooth area in centre.

Hydrotheca campanulate, very delicate, round or polyhedral in section,

0,3—-0,6 mm in depth and 0,2-0,5 mm in marginal diameter, with depth exceeding

width. Margin untoothed or with about 12 low, rounded ‘teeth’. Diaphragm

thin, straight or oblique.

Gonothecae arising in axils of thecal pedicels and occasionally from

hydrorhiza, smooth or roughly corrugated, elongated pear-shaped, with terminal

aperture on a short tubular neck. Pedicel short, annulated.

Variation. The branching is typically alternate, with longer branches near the

base of the colony and progressively shorter ones towards the tip, but extra

long branches may arise at irregular intervals, giving a pseudodichotomous

228 ANNALS OF THE SOUTH AFRICAN MUSEUM

A,D,G.H

—)

Be,

(00

Fign 73:

Obelia geniculata. A, hydrotheca and hydranth; B, stem with gonothecae containing

medusa-buds.

Obelia bicuspidata. C, stem; D, hydrotheca; E, gonotheca.

Obelia dichotoma. F, stem; G, hydrotheca with untoothed margin; H, hydrotheca with

toothed margin; J, gonotheca containing medusa-buds.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 229

appearance. Normally a branch and a hydrothecal pedicel arise together from

the same apophysis, but branches may replace hydrothecae or may arise in

pairs. Two hydrothecae may arise from the same apophysis. Hydrothecal

pedicels are variable in length and may be longer or shorter than the hydrothecae.

The geniculate appearance of some stems is the result of curvature within: the

internodes rather than at the nodes.

The margin of the hydrotheca is usually very thin and delicate with no

marginal teeth. Sometimes very low undulations may be seen, and rarely

distinct rounded teeth with indications of longitudinal striations between them.

The latter form is characteristic of O. dubia, which is here considered to be a

synonym.

The gonothecae are usually smooth or may have irregular transverse corru-

gations (typical of O. dubia).

Colonies are commonly epizootic on other hydroids and algae, and have

also been found on Squalus acutipinnis, Aulacomya magellanica, Lepas sp.

and Caretta caretta. It is very common in dock areas on pylons and ships’

hulls.

Distribution. Cosmopolitan. Type locality: south-west coast of England.

Distribution in South Africa. All round the coast, littoral to 100 m. 28/16 (s),

31/18 (1), 32/18 (s), 33/18 (s, h), 34/18 (1, s), 34/20 (s), 34/21 (s), 34/22 (s), 34/23

eisrrcl)53/25 (Ss), 29/310 hy, 26/32 (I), 25/32, 23/35 (l), 21/35

Obelia geniculata (Linnaeus, 1758)

Fig. 75A-B

Sertularia geniculata Linnaeus, 1758: 812.

Laomedea geniculata: Vervoort, 1946a: 294, figs 129-131. Leloup, 1974: 19, fig. 16.

Diagnosis. Colony usually growing on weed, particularly laminarians. Stem

unfascicled, unbranched (in South African material), reaching 22 mm, geniculate,

bearing alternate hydrothecae. Internodes not annulated or with one or two

annulations immediately above node, bearing a hydrotheca on a projecting

shoulder at distal end, with perisarc grossly thickened below the shoulder on

the side bearing the hydrotheca. Hydrothecal pedicels completely annulated,

usually shorter than the hydrotheca.

Hydrotheca campanulate, round in section, 0,16-0,3 mm in depth and

0,15-0,4 mm in marginal diameter, depth approximately equal to diameter.

Margin untoothed. Diaphragm generally thick and triangular.

Gonothecae arising in axils of thecal pedicels and from hydrorhiza, smooth,

elongated pear-shaped, with terminal aperture on a short, tubular neck. Pedicel

short, of one or two segments.

Colour: hydranths transparent.

Variation. The South African material generally has very pronounced perisarcal

thickenings in the stem internodes, and the walls of the hydrothecae are generally

230 ANNALS OF THE SOUTH AFRICAN MUSEUM

thickened as well, especially in the region of the diaphragm. The hydrotheca is

in general more stoutly built than in O. dichotoma. The diaphragm may also be

thick, resembling superficially that of Campanularia, but there is always a distinct

line separating it from the wall of the hydrotheca. The diaphragm may be

straight or oblique, in the latter case imposing a certain asymmetry on the

hydrotheca. This may be enhanced by unequally thickened thecal walls, the

abcauline side tending to be thicker than the adcauline. The length of the thecal

pedicel varies and it may have 1-8 segments. The gonothecae may arise in pairs.

Distribution. Cosmopolitan. Type locality: U.K.

Distribution in South Africa. Lideritz Bay to Cape Infanta, littoral to 80 m,

Inhaca (littoral) and on ships’ hulls, especially common on laminarians, also on

Jasus lalandii. 26/15 (1, s), 32/18 (s), 33/17 (s), 33/18 (1, s, h), 34/18 (1, s), 35/19

(s), 34/20 (s), 26/32 (1, s), 25/32

Family Syntheciidae

Diagnosis. Thecate hydroids with tubular, bilaterally symmetrical hydrothecae,

into which the hydranths can be completely withdrawn. Hydrotheca sessile,

without operculum, with untoothed margin, with a definite floor perforated by a

hydropore. Hydranth with conical hypostome and one circle of filiform

tentacles. Nematophores absent. Gonophores in the form of fixed sporosacs.

Introduction. Members of the Syntheciidae have erect stems which may be small

and unbranched, or may bear pinnately arranged hydrocladia. Both stem and

hydrocladia bear hydrothecae. The species are seldom large, and many are

minute. The stem is usually unfascicled, though fascicled in a few larger species.

Stolonization is common, particularly in the genus Synthecium, where the tips

of the stems or hydrocladia develop stolons which reunite with other parts of the

colony often resulting in a tangled, bushy network.

The arrangement of the hydrothecae is used as a basis for generic diagnosis.

They may be alternate, in opposite pairs, or in verticils.

The structure of the hydrotheca is very similar to that in the Sertularidae,

and undoubtedly the two families are very closely related. The Syntheciidae can

be distinguished by the circular, untoothed margin to the hydrotheca and by the

absence of an operculum.

The hydrotheca is sessile and seated directly on an apophysis of the stem.

Its adcauline wall is at least partly adnate to the stem, and then usually bends

away from it. There is no diaphragm in the strict sense of the term, but the floor

of the hydrotheca is well defined and perforated in the centre by a small hydro-

pore. By this feature the family can be distinguished from the Lafoeidae. In

the stronger species the base of the adcauline wall usually extends below the

level of the floor where it forms a thickened boss of perisarc. Broch (1918)

states that the hydrotheca is lined with an ectodermal lamella which is con-

tinuous with the base of the hydranth, but this has not been verified for all

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA Da

species. Broch also states that the hydranth usually possesses a BLIND CAECUM

or bulge on the abcauline side where the endodermal epithelium is low and

without digestive elements. In the South African species this caecum has been

observed only in Synthecium hians.

The gonothecae usually spring from within the hydrothecae but may arise

from the stem just below them. Stechow (1923c) used this feature to distinguish

Synthecium from Hincksella, but Billard (1925a) has shown that this is not a

good diagnostic character. When the gonothecae arise below the hydrothecae

they usually emerge through special thin areas of perisarc in this position which

have the appearance of FENESTRAE and are clearly visible in the infertile colony.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Hydrothecae alternate on stem and branches, forming two longitudinal rows

Hincksella p. 231

— Hydrothecae in opposite pairs or verticils on stem and branches br 4 ery

2. Pairs of hydrothecae always in the same plane and forming two longitudinal rows

Synthecium p. 235

— Hydrothecae in pairs or verticils, the members of one group alternating with those

of the next and forming double the number of longitudinal rows [| Staurotheca]

Genus Hincksella Billard, 1918

Diagnosis. Colony with erect stem, which may or may not bear alternate

hydrocladia. Stem and hydrocladia, when present, bearing alternate hydro-

thecae. Gonothecae springing from within hydrothecae or from stem or hydro-

rhiza.

Type species: Hincksella sibogae Billard, 1918.

KEY TO SPECIES

1. Stem unsegmented, bearing alternate, unsegmented hydrocladia .. H. echinocarpa

— Stem segmented, without hydrocladia ue ae = un a oe Rs pe PA

2. Hydrotheca adnate for about half adcauline length. Stem corrugated near nodes

H. corrugata

— Hydrotheca adnate for about one quarter adcauline length. Stem not corrugated

H. cylindrica pusilla

Hincksella corrugata Millard, 1958

Fig. 76A

Hincksella corrugata Millard, 1958: 181, fig. 5.

Diagnosis. Stem reaching 10 mm, unfascicled, unbranched, slightly zigzag,

divided by oblique nodes into internodes, each bearing a hydrotheca. Perisarc

corrugated in basal region and in neighbourhood of nodes. Hydrothecae

alternate, the two rows in one plane or displaced towards anterior surface.

Hydrotheca adnate for about half adcauline length, tubular, bent slightly

232 ANNALS OF THE SOUTH AFRICAN MUSEUM

outwards, smooth or faintly corrugated, 0,6-0,7 mm in length and 0,4-0,5 mm

in marginal diameter. Margin very slightly everted.

Gonothecae unknown.

Variation. In the few colonies known there is variation in internode length and

in the amount of corrugation on the stem and on the hydrothecal walls.

Remarks. This species may eventually prove to be a variety of H. cylindrica.

Distribution outside South Africa. Madagascar.

Distribution in South Africa. Natal to Mogambique, 10-46 m, rare. Type

locality: Natal. 30/30 (s), 26/32 (s), 21/35

Hincksella cylindrica (Bale, 1888)

Sertularella cylindrica Bale, 1888: 765, pl. 16 (fig. 7).

Synthecium cylindricum: Nutting, 1904: 136, pl. 41 (fig. 7). Fraser, 1944: 234, pl. 48 (fig. 216).

Hincksella cylindrica: Blackburn, 1937: 173, fig. 2. Vervoort, 1959: 245, figs 18-19a.

Diagnosis. Stem unfascicled, unbranched or irregularly branched, divided by

oblique nodes into internodes, each bearing a hydrotheca. Internodes without

corrugations. Hydrothecae alternate, the two rows in one plane.

Hydrotheca thin-walled, adnate for 4 to nearly 4 adcauline height, tubular,

curved slightly outwards, smooth. Margin very slightly everted.

Gonotheca arising from within hydrotheca, from stem below hydrotheca

or from hydrorhiza, sessile or with pedicel of variable length. Male elongated

and rather irregular in outline, female spherical.

Only a subspecies of this species from South Africa.

Hincksella cylindrica pusilla Ritchie, 1910

Fig. 76B-E

Sertularella cylindrica var. pusilla Ritchie, 1910b: 817, pl. 77 (fig. 9).

Hincksella cylindrica var. pusilla: Vervoort, 1968: 28, fig. 12.

Hincksella cylindrica pusilla: Millard, 1964: 22, fig. 6A—D.

Cyclonia pusilla: Hirohito, 1969: 16, fig: 12.

Diagnosis. A dwarf form differing from the nominate subspecies in the following

characters:

Stem never branched, shorter (reaching 7 mm) and with more slender

internodes (diameter under 0,1 mm).

Hydrotheca adnate for about 4 adcauline height, more slender and more

definitely bent outwards near base, 0,5-0,6 mm in depth and 0,14-0,17 mm in

marginal diameter.

Variation and remarks. The most obvious variation in the single sterile colony

found is in the length of the internodes, which is very variable. The hydrothecae

are so delicate that they crumple easily and a perfect one is seldom seen. There

appears to be a certain amount of variation in shape, some being obviously

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 233

Fig. 76.

Hincksella corrugata. A, stem.

Hincksella cylindrica pusilla. B-D, hydrothecae; E, part of stem with characteristically

crumpled hydrothecae.

Hincksella echinocarpa. F, stem; G, origin of hydrocladium.

Scale: F in cm, the rest in mm/10.

234 ANNALS OF THE SOUTH AFRICAN MUSEUM

tubular and of equal diameter throughout, and others expanding slightly towards

the margin.

Hirohito (1969) has for the first time described and illustrated the gono-

phores of subspecies pusilla. These show sexual dimorphism and arise either from

within a hydrotheca or direct from the hydrorhiza. They are similar to those of

the nominate subspecies and explain the apparent discrepancies in the literature,

those of Torrey 1902 (repeated in Nutting 1904) being male, and those of Fraser

(1944) and Blackburn (1937) apparently being female.

Distribution outside South Africa (of subspecies pusilla). Mergui Archipelago

(type locality), East Indies, Japan, tropical West Africa, West Indies, Caribbean.

Distribution in South Africa. One record only, from the Agulhas Bank in 84 m.

33/28 (s) |

Hincksella echinocarpa (Allman, 1888)

Fig. 76F—G

Sertularia echinocarpa Allman, 1888: 57, pl. 28 (figs 1—-1a).

Hincksella echinocarpa: Millard, 1967: 176} fig. 3A—C.

Diagnosis. Stem reaching a height of 90 mm; fascicled, though flexuous and

unable to support itself out of fluid: unbranched; bearing alternate hydrothecae

and alternate, flexuous hydrocladia which generally arise below every third

hydrotheca; unsegmented. The two rows of hydrothecae and hydrocladia in

one plane.

Hydrocladium separated from stem apophysis by oblique node, unfascicled,

unsegmented, reaching a maximum length of 40 mm, bearing alternate

hydrothecae.

Hydrotheca adnate for less than half adcauline height, tubular, with free

part straight or curved slightly outwards, smooth, 1,2—1,3 mm in total adcauline

length (adnate plus free part) and 0,3-0,5 mm in marginal diameter.

Gonothecae (not reported in South Africa) borne below hydrothecae,

where thin oval areas occur in the perisarc. ‘Pyriform, thickly set with hollow,

blunt, spine-like outgrowths of their chitinous perisarc’ (Allman).

Variation. As in many deep-water species the hydrorhiza forms a branching,

fibrous rootstock for penetration of a muddy substratum.

The stem is lax and geniculate for the most part, though it may be straight

in the distal unfascicled portion. Variations occur in the distance between

consecutive hydrocladia, with corresponding variations in the number of inter-

mediate hydrothecae. Rarely a transverse node occurs in the hydrocladium

immediately above a hydrotheca; this appears to be the result of regeneration

rather than a normal node. Rarely, too, the hydrocladium may rebranch.

Allman reports a height of 160 mm in material from Kerguelen.

Distribution outside South Africa. Only record and type locality: Kerguelen

Island in southern Indian Ocean.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 235

Distribution in South Africa. Off the coast of Mocambique in | 610-2 200 m.

24/36 (a), 23/37 (a)

Genus Synthecium Allman, 1872

Diagnosis. Colony with erect stem usually (always, in South African species)

bearing hydrocladia in opposite pairs. Stem and hydrocladia bearing hydro-

thecae in opposite pairs, the pairs always in the same plane and thus forming

two longitudinal rows. Gonothecae usually dioecious, springing from within

hydrothecae.

Type species: Synthecium elegans Allman, 1872.

KEY TO SPECIES

1. Hydrotheca widening strongly to margin .. at bas ie = S. hians

— Hydrotheca tubular, not widening markedly to margin ae ; Ae perme v2,

2. Hydrotheca with one adcauline internal tooth in at least some Bydvothecds S. dentigerum

— Hydrotheca never with internal tooth “3 ne i Ae a .. 3S. elegans

Synthecium dentigerum Jarvis, 1922

Fig. 77E-H

Synthecium dentigerum Jarvis, 1922: 344, pl. 25 (fig. 15). Totton, 1930: 172. Millard, 1964:

24, fig. 6E-J. Watson, 1973: 169, figs 17-18.

Diagnosis. Stem reaching a height of 40 mm; unfascicled; normally unbranched,

but bearing pinnately arranged hydrocladia; divided by straight nodes into

internodes, which bear a variable number of hydrocladia and hydrothecae.

The two rows of hydrocladia in the same plane.

Hydrocladium making a wide angle with stem, with straight nodes and one

pair of hydrothecae to each internode. Hydrothecae opposite, though

subopposite in proximal region.

Hydrotheca adnate for over half adcauline length, tubular, curved out-

wards, 0,5—0,6 mm in total adcauline length (adnate plus free part) and 0,16-

0,2 mm in marginal diameter. With one large internal tooth on adcauline side

in at least some hydrothecae of colony.

Gonotheca arising from within hydrotheca, pentagonal or triangular in

section, tapering distally, annulated, with 5-6 transverse folds on each flat

side, with small circular distal opening.

Variation. Branching occasionally occurs, the branches replacing hydrocladia.

The nodes of the stem may be indistinct in certain regions. On the internodes

the following are the most common arrangements:

(i) two pairs of hydrothecae, with a pair of hydrocladia between them,

(ii) one pair of hydrocladia followed by a pair of hydrothecae,

(iii) one pair of hydrothecae only.

Stolonization is common.

The presence of an internal hydrothecal tooth is a variable character.

236 ANNALS OF THE SOUTH AFRICAN MUSEUM

When present it is usually large and very obvious, but it may be present in only

a few hydrothecae of a colony, and is often present in one member of a pair

and absent in the other. Occasional hydrothecae also possess an internal peg-

like thickening of perisarc in the centre of the abcauline wall.

The typical pentagonal gonothecae sometimes have two of the angles

smoothed out giving the appearance of a rather flattened triangle. The annu-

lations tend to fade out on the angles, though occasionally continue right over

them. There is never a definite zigzag line as in S. elegans.

Distribution outside South Africa. Tropical Indian Ocean: Chagos (type locality)

and Seychelles. South Australia.

Distribution in South Africa. Sparsely distributed on the Agulhas Bank in 18-—

46 m. 34/19 (s), 34/21 (s), 33/25 (s), 34/25 (s), 33/26 (s), 33/27 (s)

Synthecium ?elegans Allman, 1872

Fig. 77A—B

Synthecium elegans Allman, 1872: 229, fig. Allman, 1876: 266, pl. 15 (figs 1-3). ?Millard,

1957: 203, fig. 9D.

Synthecium ramosum Allman, 1886: 137, pl. 12 (figs 3-4).

Synthecium subventricosum Bale, 1914a: 5, pl. 1 (figs 3-5).

pt eee forma subventricosum: Ralph 1958: 347, fig. 16a—h. Watson, 1973: 167,

nace ia forma elegans: Ralph, 1958: 349, fig. 17a-e.

Diagnosis. Stem reaching a height of 20 mm; unfascicled; bearing pinnately

arranged hydrocladia; divided by straight nodes into internodes, each of which

normally bears two pairs of hydrothecae and one pair of hydrocladia arising

between them. The two rows of hydrocladia in the same plane.

Hydrocladium with regular nodes, each internode bearing a pair of hydro-

thecae. Hydrothecae opposite, though subopposite in proximal regions.

Hydrotheca adnate for over 3? height, tubular, curved outwards, 0,5—1,0

mm in total adcauline length (adnate plus free part) and 0,2-0,4 mm in marginal

diameter.

Gonotheca (not reported from South Africa) arising from within hydro-

theca, ovate, with prominent transverse ridges connected on two sides by zig-

zag longitudinal ridges, with distal aperture on short tubular neck.

Variation. South African material is unbranched, but Allman (1886) reports

branching specimens from New Zealand reaching a height of 150 mm. The

branches replace hydrocladia. Simple stems resembling solitary hydrocladia may

also occur.

The arrangement on the stem internodes is very variable, particularly in

the older regions, and apart from the normal arrangement each internode may

bear

(i) one pair of hydrocladia only,

(ii) one pair of hydrothecae only,

(ili) one pair of hydrocladia followed by one pair of hydrothecae.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 237

a é ~~

B.G H

Fig. 77.

Synthecium elegans. A, hydrocladium; B, stem.

Synthecium hians. C, stem and hydrocladia from young part of colony; D, hydrocladium.

Synthecium dentigerum. E, hydrocladium; F, gonotheca in side view; G, a branching stem;

H, gonotheca viewed from above, X marks adcauline side.

Scale: B and G in cm, C in mm, the rest in mm/10.

238 ANNALS OF THE SOUTH AFRICAN MUSEUM

The hydrocladia may have indistinct nodes, and may occasionally be

branched. Stolonization is common.

Remarks. The identification of this species must remain doubtful until the

discovery of gonophores in this country, for the trophosome is similar to that of

several other related species. The same applies to records of S. elegans outside

the country. These are marked with a query in the distribution. Material from

the Seychelles has recently been definitely identified as S. patulum (Busk) by

Millard & Bouillon (1973).

Distribution outside South Africa. New Zealand (type locality), Australia, East

Indies, 7Madagascar, ?East Africa.

Distribution in South Africa. Sparsely distributed from False Bay, Cape, to

Mocambique in 16-100 m. 34/18 (s), 35/19 (s), 34/22 (s), 34/24 (d), 30/30 (s),

29/31 (s), 28/32 (s), 24/34 (s), 21/35

Synthecium hians Millard, 1957

Fig. 77C—D

Synthecium hians Millard, 1957: 204, fig. 9A—-C.

Diagnosis. Stem reaching a height of about 60 mm; unfascicled; normally

unbranched, but bearing pinnately arranged hydrocladia; divided by straight

nodes into internodes, each of which normally bears three pairs of equally

spaced hydrothecae and one pair of hydrocladia arising below the second pair

of hydrothecae. The two rows of hydrocladia in the same plane.

Hydrocladium with irregular nodes; bearing pairs of opposite hydrothecae

which may be subopposite in proximal regions.

Hydrotheca adnate for almost entire length, narrow at base, widening

strongly to margin, bent very slightly outwards, 0,3-0,4 mm in total adcauline

length (adnate plus free part) and 0,2-0,3 mm in marginal diameter. Margin

everted. No internal teeth. Hydranth with abcauline caecum.

Gonotheca unknown.

Variation. In rich colonies the hydrorhizal tubes may rise up from the surface in

a tangled bundle simulating a fascicled stem, the individual tubes anastomosing

with one another and with the bases of the stems.

The nodes of the stem may be indistinct in the older regions. The arrange-

ment on the stem internodes sometimes varies and the following aberrations

may occur:

(i) two pairs of hydrothecae per internode, with a pair of hydrocladia arising

below the second pair,

(ii) one pair of hydrothecae only per internode.

In rare cases a normal hydrocladium may be replaced by a branch.

The young hydrocladium commences with an unpaired abcauline

hydrotheca, which is followed by subopposite pairs gradually changing to

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 239

opposite. In older parts of the colony (possibly due to regeneration) the hydro-

cladium is separated from the stem by a transverse node, after which opposite

or nearly opposite pairs of hydrothecae start immediately. The angle between

the hydrocladium and the stem is large in the older part of the colony (almost a

right angle) but tends to become more acute in the younger region.

The hydrothecae are very constant in shape though on older stems the

delicate distal parts have become eroded leaving low cup-shaped scars.

Distribution. Endemic to South Africa. Type locality: False Bay, Cape.

Distribution in South Africa. Fairly common round the coast from False Bay

in the Cape to Mocambique in 18-219 m. 34/18 (s), 34/20 (s), 34/21 (s), 34/22

(s), 34/23 (d), 34/25 (s), 33/26 (s), 33/27 (s), 33/28 (s), 32/28 (s), 30/30 (s), 29/31

(s, d), 29/32 (s), 28/32 (s, d), 24/35 (d)

Family Sertulariidae

Diagnosis. Hydrothecae borne on stem and hydrocladia in two or more longi-

tudinal rows. Hydrotheca stalked or sessile and, if sessile, adnate to a varying

degree, bilaterally symmetrical, usually with a toothed margin and a hinged

operculum of one or more valves, with a diaphragm in stalked species and a

definite floor perforated by an asymmetrical hydropore in sessile species.

Hydranth with a single circle of filiform tentacles and a conical hypostome;

endoderm differentiated into an aboral and an oral region, the former some-

times forming an abcauline caecum on contraction. Nematothecae absent.

Gonophores in the form of fixed sporosacs.

Introduction. The Sertulariidae is one of the largest families of Hydroida and is

easily recognized by its bilaterally symmetrical and operculate hydrothecae.

In only one genus (Calamphora) is the colony stolonial, in all others the

hydrothecae are borne on an erect stem.

The stem may be fascicled or unfascicled, branched or unbranched. Charac-

teristically branches arise in one plane and are opposite or alternate, often

rebranching in the same way, though species with spiral or whorled branches

also occur. In some cases the branches differ from the main stem in some way

(e.g. in thickness, arrangement of hydrothecae) and the term hydrocladia is

appropriate. In others, and particularly in the small, irregularly branched

species, the branches are similar in structure to the stem, but for the sake of

uniformity the term hydrocladia is used here too for the final ramifications of

a pinnate stem.

The stem is termed STIFF when it is able to support itself out of fluid and

FLEXUOUS when it cannot. Stiff stems give rise to bushy colonies, and flexuous

stems to long, straggling colonies. Stolonization from the ends of the stem or

hydrocladia may occur in any species and is particularly common in

Symplectoscyphus and Dictyocladium. It gives the colony a tangled and matted

appearance.

240 ANNALS OF THE SOUTH AFRICAN MUSEUM

Stem and branches are typically segmented, with transverse or oblique

nodes. Each internode may bear one or more hydrothecae and may contain

internodal septa. In certain species of Sertularia HINGE-JOINTS occur, which

allow for movement and provide a point of easy rupture and subsequent

regeneration. Hinge-joints usually occur in pairs near the base of an unbranched

stem or at the bases of the hydrocladia of a branched stem, but may also occur

at irregular intervals in addition to the normal nodes.

The arrangement of the hydrothecae on the stem and hydrocladia varies.

Commonly the hydrothecae are alternate (e.g. in Sertularella and Symplecto-

scyphus) or in opposite pairs (e.g. in many species of Sertularia), but they may

be subalternate or subopposite. In all of these the hydrothecae form two longi-

tudinal rows. Members of the two rows may be well separated or may be

CONTIGUOUS and touch one another in the centre on one surface. Occasionally

the hydrothecae form more than two longitudinal rows (e.g. in Selaginopsis and

Dictyocladium). In Hydrallmania the hydrothecae are borne in a single row on

one surface of the stem, but their distal ends are bent alternately to left and to

right.

Most of the Sertulariidae have sessile and bilaterally symmetrical hydro-

thecae, with one side adnate to the stem to a varying degree. In some of the more

specialized genera such as Thuiaria and Salacia all, or almost all, of one surface

of the hydrotheca may be adnate and deeply sunk into the stem. Associated

with the adnate condition the hydrotheca is usually curved, with the mouth

directed away from the stem, but there may also be a double curvature—

outwards and then distally.

In the genus Sertularella with its numerous species the curvature of the

hydrotheca is important in diagnosis and thus needs precise definition. Three

categories are recognized:

1. Margin perpendicular to axis. Hydrotheca not curved, and flask-shaped in

lateral view. A line dropped at right angles to the margin and through its

centre will bisect the hydrotheca and pass through the base of the adcauline

wall.

2. Margin tilted towards abcauline side. Hydrotheca curved away from stem. A

line dropped at right angles to the margin and through its centre will pass

through the adcauline wall.

3. Margin tilted towards adcauline side. Hydrotheca with double curvature. A

line dropped at right angles to the margin and through its centre will pass

through the abcauline wall or through the hydropore.

Because of the curvature of the hydrotheca measurements may be difficult.

In this work the marginal diameter and the abcauline length of the hydrotheca

are usually given, and these are taken in lateral view, the length being measured

as a straight line from the floor of the hydrotheca to the abcauline margin

across any curvature which may be present. Occasionally the abcauline length

cannot be measured accurately because the floor does not reach the abcauline

wall. In such cases the adcauline length is given instead. Measurements are

always exclusive of any additional margins resulting from regeneration.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 241

erculum 5;

OR adcauline side

marginal tooth

internal tooth y

adnate part

intrathecal

abcauline side septum

contiguous part

hydropore internode

node

| 1 Moe joint

SERTUPAREELA

SERTULARIA

abcauline

length

Margin perpendicular tilted towards tilted towards

to axis abcauline side adcauline side

SHAPE IN SERTULARELLA

Fig. 78.

Sertulariidae: hydrothecal shape and structure.

Possibly as a result of curvature the hydrotheca may have internal folds,

Or INTRATHECAL SEPTA, and these may be adcauline or abcauline or on both sides.

They form a useful point of attachment for the hydranth and are characteristic

of many species of Sertularia and of the genus Crateritheca.

In the sessile species the hydrotheca has a definite floor of perisarc with an

excentric hydropore. The hydropore is close to the abcauline side, and the

floor is attached to, and continuous with, the base of the adcauline wall. The

adcauline wall is often produced below the floor as a thickened knot of perisarc.

Also included in the Sertulariidae are a few genera with stalked, yet oper-

culate, hydrothecae. These have in the past been included variously in the

Campanulinidae, Campanulariidae and Sertulariidae. Mammen (1965a) created

for them a new family, the Thyroscyphidae. Of these, the genera Thyroscyphus

and Parascyphus were reviewed by Splettstésser (1929), who also created a

new genus, Cnidoscyphus, for certain species on the basis of nematocyst

structure and arrangement. (Cnidoscyphus is not recognized in the present work,

242 ANNALS OF THE SOUTH AFRICAN MUSEUM

for the author feels that nematocyst structure and arrangement are not suffi-

cient grounds for separating genera which are otherwise very similar.) These

genera are usually considered to be more primitive than the sessile genera and

to differ from them in the presence of a diaphragm in the hydrotheca. It is

felt, however, that the diaphragm is strictly comparable with the floor of

the sessile hydrothecae where the pedicel has been eliminated. The stolonial

genus Calamphora in fact bridges the gap. Calamphora has unmistakable

affinities with Sertularella and was not included in the Thyroscyphidae by

Mammen. Its solitary hydrotheca has a diaphragm of the thyroscyphid type,

but Leloup (1935: 35) illustrated a colony of C. parvula (under the name of

Thyroscyphus intermedius f. peculiaris) with two hydrothecae to a stem, in which

the proximal one is sessile and adnate as in a typical Sertularella. These pedi-

cellate genera are here retained in the Sertulariidae.

In the Sertulariidae the margin of the hydrotheca is typically toothed,

and the number and shape of the teeth are useful in diagnosis. For instance,

Sertularella has four marginal teeth, Symplectoscyphus three and Amphisbetia

two. In a few forms the marginal teeth are almost obsolete (e.g. in Jdiellana) or

absent (Abietinaria, Thuiaria).

OC aa

4 valves 3 valves adcauline abcauline hinge hinge

4 teeth 3 teeth larger larger adcauline abcauline

PYRAMID-SHAPED 2 VANES 2a BEM 1 VALVE

Fig. 79.

Sertulariidae: marginal teeth and opercular valves (adcauline side on right).

In addition to the marginal teeth some species have INTERNAL TEETH

formed by pegs of perisarc projecting into the cavity of the hydrotheca just

below the margin. These are particularly prevalent in Sertularella, where in

certain cases their presence or absence, number and position may be diagnostic

for the species.

The mouth of the hydrotheca is closed by an OPERCULUM consisting of one

or more valves hinged at the edge. In genera with three or four marginal teeth

a similar number of valves is seated in the bays between them and meet in the

centre to form a pyramid, e.g. Sertularella, Symplectoscyphus, Thyroscyphus.

Genera with two marginal teeth, as for instance Sertularia, Amphisbetia and

Dynamena, have an operculum of two valves of unequal size attached at the ad-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 243

and abcauline edges. The larger valve is adcauline in Amphisbetia and abcau-

line in Dynamena and Sertularia. In these forms the adcauline valve may be

divided into two by a partition and bent at an angle like a roof. Genera with

only one large opercular valve include Diphasia, Idiellana, Abietinaria, Thuiaria

and Salacia. The hinge is adcauline in the first three and abcauline in the last

two; it is often seated in an embayment of the margin. Sometimes the operculum

is shed fairly early in development, as in some species of Thyroscyphus, or

reduced to a membrane, as in Crateritheca acanthostoma, or even lost altogether,

as in Stereotheca. These genera thus show relationship to the Syntheciidae, but

are retained in the Sertulariidae because of the toothed hydrothecal margin.

Naumov (1960) suggests that the number of opercular valves provides an

example of the evolutionary process of oligomerization, those with many

valves being primitive and those with one or none being advanced. On con-

traction the hydranth is completely withdrawn into the hydrotheca and the

operculum closed over it. Regeneration of the margin is accompanied by

regeneration of the operculum, so that there may be several opercula, one above

the other.

22 OC

Se BIE Wa d\ Mele lal

Fig. 80.

Sertularella: internal teeth (adcauline side on right).

In certain genera (Abietinaria, Amphisbetia, Calamphora, Crateritheca,

Hydrallmania, Parascyphus, Sertularella, Sertularia, Symplectoscyphus and

Thuiaria) contraction of the hydranth into the hydrotheca causes the proximal

part of the gastral cavity wall to be folded into a BLIND CAECUM on the abcau-

line side. This is due in part to the attachment of the ectoderm of this region

to the hydrothecal wall preventing its complete withdrawal. This blind caecum

is useful in generic diagnosis, but it must be borne in mind that it can only be

observed in the contracted hydranth. It imparts a bilateral symmetry to the

hydranth. In other genera the hydranth is withdrawn symmetrically into the

hydrotheca and there is no caecum, e.g. Dictyocladium, Diphasia, Dynamena,

Idiellana and Salacia. In Thyroscyphus withdrawal of the hydranth causes an

annular folding all round the body, and Splettstésser (1929) considers this to be

an early stage in the evolution of a blind caecum.

244 ANNALS OF THE SOUTH AFRICAN MUSEUM

nematocyst

batteries

ectoderm lining

hypostome

ectoderm

annular

endoderm fold

Fig. 81.

Sertulariidae: structure of hydranth (shown retracted) in diagrammatic l.s. A, with blind

caecum, e.g. Sertularella; B, without caecum, e.g. Dynamena; C, with annular fold, e.g,

Thyroscyphus.

The ectoderm of the hydranth is produced as a lining over the inner wall

of the hydrotheca to a varying degree, and in Thyroscyphus may form a “Decken-

platte’ below the operculum. To this lining of ectoderm the ectoderm of the

hydranth is fastened in certain strategic positions where perisarcal thickenings

of the hydrotheca may develop. Although Mammen (1965a), following Nutting

(1904), speaks of ‘protractor’ and ‘retractor’ muscles, to the author’s knowledge

actual muscle fibres have as yet not been identified in these attachments. Nema-

tocysts may in certain cases be present in the lining ectoderm or in the ‘Decken-

platte’, and it was on this feature that Splettst6sser (1929) based his genus

Cnidoscyphus.

A peculiar structure is present in Sertularia ligulata (Fig. 100D) and_is

possibly present in other species too (it has been seen in S. turbinata). This 1s

the LIGULA. It. consists of a slender outgrowth from the base of the adcauline

side of the hydranth and it protrudes as a leaf-shaped process through the mouth

of the hydrotheca. It often remains clearly visible after the hydranth has con-

tracted. Its function is not clear, but since it is well armed with nematocysts,

it may serve as a nematophore. Although nematothecae do not occur in the

Sertulariidae, in Amphisbetia minima certain small pores occur with some

regularity on the internodes of the stem and each is usually surrounded by a low

collar of perisare (Fig. 82H). They have sometimes been called nematothecae, but

there is as yet no proof of the presence of nematophores.

The gonothecae are usually dioecious and sometimes also dimorphic. No

special protective structures are developed around them and they are not

aggregated, but the perisarc may be transversely annulated or sculptured with

an elaborate arrangement of spines. The eggs are usually fertilized in situ and

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

245

the planulae developed within the gonotheca. In some species the developing

eggs are extruded through the opening of the gonotheca into an acrocyst

(Fig. 90B). In Diphasia and Sertomma the spiny processes of the gonotheca may

bend over and meet in the centre to enclose a brood-chamber or MARSUPIUM.

There has been much disagreement over the limitations of genera in

the

Sertulariidae, Broch (1918) recognizing only a few (9), and Stechow (1923c)

a large number (36). The present work adopts an intermediary course, and for

the limitations of the genera Diphasia, Dynamena and Salacia the views of

Billard (1925a) have been accepted.

10.

f2.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

Hydrotheca stalked

Hydrotheca sessile

Colony stolonial .. a me sit a a Be Calamphora p.

Colony with upright stem .. a = se ais

Hydrotheca with four marginal hen al eee ie of four valves. Hydranth

with annular fold, but no caecum ot Thyroscyphus p.

Hydrotheca with three marginal teeth and operculum of three valves (in South

African species). Hydranth with abcauline caecum ce ay Parascyphus p.

Hydrotheca with more than four marginal teeth ;

Hydrotheca with no marginal teeth, or with four or less

Hydrotheca with internal ridges or septa oe Be an Crateritheca p.

Hydrotheca without internal ridges or septa... te = Stereotheca p.

Hydrothecal operculum in form of pyramid, consisting of three or four valves.

Margin with three or four teeth of equal size

Operculum not in form of pyramid. Margin not as above; with no ) teeth, two

teeth, or three-four teeth not equal in size

Hydrothecae arranged in more than two longitudinal rows in at least some

parts of stem : iy Dictyocladium p.

Hydrothecae alternate and arranged i in two longitudinal rows only

Hydrotheca with four marginal teeth and operculum of four valves. Mouth

quadrangular : Sertularella p.

Hydrotheca with three marginal ‘teeth and operculum of three valves. Mouth

triangular

Hydrothecae alternate. Hydranth with abcauline caecum Bee cere is p.

Hydrothecae opposite. Hydranth without abcauline caecum .. [Sertomma]

Operculum of two valves, the adcauline one sometimes divided into two.

Hydrotheca with two marginal teeth (and sometimes a minute median,

adcauline one as well) Be

Operculum of one valve. Hydrothecal margin generally ‘not toothed (but

toothed in Diphasia tetraglochina)

Bases of hydrothecae forming one longitudinal row, their distal ends bending

alternately to right and left. Adcauline valve of operculum the larger Hydrallmania p.

Bases of hydrothecae eumine two apie rows, more or less on the

sides of the stem

Marginal teeth of Beas near abcauline oe aesaude opercular valve

larger than abcauline. Hydranth with abcauline caecum ay Amphisbetia p.

Marginal teeth of hydrotheca more or less midway between adcauline and

abcauline edge. Abcauline opercular valve larger than adcauline

269

247

246 ANNALS OF THE SOUTH AFRICAN MUSEUM

13. Hydranth without abcauline caecum. Hydrothecal Ba typically (though not

always) grouped... Dynamena p. 261

— Hydranth with abcauline caecum. Hydrothecal pairs never prouped Sertularia p. 305

14. Operculum adcauline ae 308 ee se ae ie ce be 15

— Operculum abcauline ee : Bee 17

15. Hydrotheca expanding distally. gaan without caneaunes caecum Diphasia p. 256

— Hydrotheca not expanding distally ae , ek : 16

16. Hydranth without abcauline caecum. fay aromnGese all on one ate of

hydrocladium : ai Idiellana p. 269

— Hydranth with abcauline | caecum. " Hydrothecae on lateral surfaces of hydro-

cladium a 3 ie ae a es se oe Abietinaria p. 246

17. Hydrothecae in more than two longitudinal rows a ee mae

— Hydrothecae in two longitudinal rows .. aa i Pe 18

18. Hydranth with abcauline caecum .. o Ry. s ats ae Thuiaria p. 320

— Hydranth without abcauline caecum ae? a ue x = Salacia p. 271

Genus Abietinaria Kirchenpauer, 1884

Diagnosis. Stem erect, bearing hydrothecae, and sometimes hydrocladia as well,

in two longitudinal rows. Hydrocladia different in structure to stem, with inter- .

nodes of irregular length. Hydrotheca sessile, partly adnate, flask-shaped and

wider at base than at margin, without distinct marginal teeth. Operculum of

one large adcauline valve. Hydranth with abcauline blind caecum.

Type species: Sertularia abietina Linnaeus, 1758.

One species from South Africa and one doubtful record.

Abietinaria laevimarginata (Ritchie, 1907)

Fig. 82F-G

Sertularia laevimarginata Ritchie, 1907a: 507, pl. 26 (figs 5-6).

Sertularia linealis Warren, 1908: 308, fig. 9. Millard, 1958: 195, fig. 8D, G.

rate laevimarginata: Gravier, 1972: 8, fig. 2C. Millard & Bouillon, 1974: 27, fig. 7A—C,

non Sertularia linealis var. longa Millard, 1958: 197, fig. 8E.

non Sertularia linealis: Millard, 1968: 272.

non Sertularia linealis longa: Millard & Bouillon, 1973: 75, fig. 9E-F.

Diagnosis. Hydrorhiza growing on weed and typically arranged in longitudinal

lines, without strengthening pegs of perisarc, but usually with four ingrowing

perisarcal lobes around origin of stem. Stem unfascicled, unbranched, reaching

a maximum height of 5 mm, each internode bearing a pair of opposite hydro-

thecae. Two (or rarely three) hinge-joints present near base of stem below

thecate part, remaining nodes slightly oblique or indistinct. Members of a pair

of hydrothecae contiguous in front (except sometimes for the basal pair),

separate behind, their free adcauline walls typically forming a straight line at

right angles to the axis of the stem.

Hydrotheca adnate for over half adcauline length, bent outwards, narrow-

ing to margin and usually constricted just below it, with no intrathecal ridge,

with thick perisarc, 0,13-0,3 mm in abcauline height and 0,08-0,11 mm in

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 247

marginal diameter. Margin especially thick on adcauline edge, with two low,

rounded lateral lobes. Internal teeth present, one large adcauline, which may be

double, and two low latero-abcauline. Operculum shed early.

Gonotheca borne on front of stem below first pair of hydrothecae, smooth,

compressed, spherical to ovoid in broad view, with a wide distal operculate

aperture on a low collar, reaching 1,0 mm in length and 0,8 mm in maximum

diameter.

Variation. The shape of the hydrotheca changes along the length of the stem,

the distal ones being more erect and contiguous for a greater length than the

basal ones. The free adcauline walls of the distal pair may thus not form a

straight line but subtend an obtuse angle between them. The marginal lobes of

the hydrotheca vary in development and may be quite distinct or almost obsolete.

Distribution outside South Africa. Cape Verde Islands (type locality), tropical

western Indian Ocean, including Madagascar, Wasin, Cargados and Chagos.

Distribution in South Africa. Northern Natal and Mocambique, on weed in

shallow water. 25/32, 26/32 (s), 27/32

Doubtful species

Abietinaria abietina (Linnaeus, 1758)

Sertularia abietina Linnaeus, 1758: 808. Busk, 1851: 118. Hincks, 1868: 226, pl. SO.

Abietinaria abietina: Vervoort, 1946a: 237, figs 103-105. Millard, 1961: 204. Redier, 1963: 640.

Remarks. There is only one record of this species from South Africa, that of Busk in

1851. Although Busk’s material was correctly identified (Millard 1961), his locality is

subject to doubt since the species has not been reported again. The only recent record

from the Indian Ocean is that of Redier (1963) from Madagascar.

Genus Amphisbetia L. Agassiz, 1862

Syn. Odontotheca Levinsen, 1913.

Diagnosis. Stem erect, branched or unbranched. Stem and hydrocladia bearing

hydrothecae in two longitudinal rows. Hydrothecae sessile, partly adnate,

with two prominent marginal teeth seated near abcauline edge and occasionally

a small, median adcauline one. Operculum of two valves, a larger adcauline

one and a smaller abcauline one. Hydranth with abcauline blind caecum.

Type species: Sertularia operculata Linnaeus, 1758.

KEY TO SPECIES

1. Stem unbranched, Members of a pair of hydrothecae contiguous with one another, at

least in distal region of stem a: i of ine a A, minima

— Stem branched. Members of a pair of hydrothecae never contiguous with another .. 2

2. Stem branching dichotomously. Stem and branches similar, with one pair of hydro-

thecae to each internode (though nodes sometimes not clearly defined) A. operculata

— Branching alternate. Stem with three hydrothecae and a branch (hydrocladium) to each

internode, hydrocladia with a variable number of hydrothecae to an internode

A. maplestonei

248 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 82.

Amphisbetia maplestonei. A, part of stem showing gonotheca and origins of hydrocladia;

B, stem; Cand D, hydrotheca with and without internal teeth; E, margin of hydrotheca

with operculum.

Abietinaria laevimarginata. F, stem with gonotheca, drawn from Warren’s holotype of

Sertularia linealis; G, distal part of hydrotheca with near wall removed to show internal

teeth and opercula.

Amphisbetia minima. H, two pairs of hydrothecae; J, stem with gonotheca; K, margin of

hydrotheca with operculum.

Scale: B in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 249

Amphisbetia maplestonei (Bale, 1884)

Fig. 82A—E

Sertularia maplestonei Bale, 1884: 70, pl. 6 (fig. 4), pl. 19 (fig. 2).

Sertularia bidens Bale, 1884: 70, pl. 6 (fig. 6), pl. 19 (fig. 1). Warren, 1908: 310, fig. 10.

Thuiaria maplestonei: Billard, 1907a: 349, fig. 5, pl. 25 (figs 2-6).

Amphisbetia bidens: Millard, 1957: 220. Millard, $958: 182.

Diagnosis. Stem unfascicled, flexuous to stiff, unbranched or branching

irregularly near base, pinnate, geniculate, reaching a maximum height of 130

mm. Basal part athecate and acladiate, with a variable number of transverse

nodes. Distal part divided into regular internodes by oblique nodes sloping in

alternate directions. Each internode bearing one hydrocladium and three hydro-

thecae, one in axil and a subopposite pair above. Hydrocladia alternate, the

two rows in one plane.

Hydrocladium narrower than stem, divided by straight nodes into inter-

nodes bearing a variable number of subopposite pairs of hydrothecae. Members

of a pair of hydrothecae not contiguous.

Hydrotheca adnate for half to three-quarters adcauline length, the adnate

part sac-shaped and curved outwards, the free part narrowing to margin and

curved upwards, 0,2-0,3 mm in abcauline height (without teeth) and 0,07-

0,10 mm in marginal diameter. Margin with two long and bluntly rounded

latero-abcauline teeth. An internal perisarcal peg present on abcauline wall at

a quarter to a third of height. Internal teeth present or absent. Hydranth with

13-14 tentacles.

Gonothecae borne on stem and hydrocladia, smooth, flat-triangular in

section, pear-shaped in broad view, with two hollow distal spines arising above

two of the angles and a terminal operculate aperture on a low collar, reaching

1,7 mm in height and 0,9 mm in maximum diameter.

Colour pale brown.

Variation. One or two hinge-joints may separate the basal athecate part of the

stem (which is of variable length) from the distal part. Stem nodes may be

indistinct in parts.

The two rows of hydrothecae on the hydrocladium are usually in one plane,

but may be shifted towards the anterior surface. Hydrocladia occasionally

branch, when the cauline arrangement is reassumed for a short interval.

The more distal hydrothecae tend to be longer than the proximal ones

and to have better developed marginal teeth. The two marginal teeth are often

unequally developed. The internal teeth, when present, vary in number from

one (adcauline) to four (two adcauline and two abcauline.)

The gonotheca rarely has a third distal spine.

Distribution outside South Africa. Australia, Madagascar and Vema Seamount

(South Atlantic). Type locality: Portland, Australia.

Distribution in South Africa. False Bay to Richard’s Bay, littoral to 84 m.

250 ANNALS OF THE SOUTH AFRICAN MUSEUM

34/18 (s), 34/22 (s), 34/23 (1, s), 33/25 (s), 34/25 (s), 33/26 (s), 33/27 (s), 31/29

(1, s), 30/30 (1, s), 29/31 (s), 28/32 (s)

Amphisbetia minima (Thompson, 1879)

Fig. 82H-K

Sertularia minima D’Arcy Thompson, 1879: 104, pl. 17 (fig. 3). Bale, 1884: 89, pl. 4 (figs

9-10), pl. 19 (figs 12-13). Bale, 1915: 269. Billard, 1910: 17.

Amphisbetia minima: Ralph, 196la: 774, fig. 8a—h. Watson, 1973: 179, figs 38-39.

Diagnosis. Hydrohiza creeping on weed, with internal thickenings of perisarc.

Stem short, reaching a maximum height of 6 mm, unfascicled, unbranched;

with a very short basal athecate part terminated by 1-3 hinge-joints and a long

distal part bearing up to 15 pairs of hydrothecae, one pair to an internode.

Normal nodes narrow, oblique. Members of a pair of hydrothecae contiguous

in front (except sometimes for the basal few), separate behind.

Hydrotheca tubular, curved outwards, almost or completely adnate, with

no intrathecal ridge, 0,12-0,2 mm in abcauline height (without teeth) and

0,07—0,12 mm in marginal diameter. Margin facing upwards, with two prominent

latero-abcauline teeth.

One or two pores commonly present on at least some internodes, situated

on the antero-lateral edges of the internode below the hydrothecae, usually

surrounded by a low perisarcal collar.

Gonothecae borne on front of stem, one to each, near base and below first

or second thecal pair, compressed antero-posteriorly, smooth, pear-shaped in

broad view, with terminal operculate aperture on low collar, reaching a height

of 1,5 mm and a maximum diameter of 1,0 mm, male and female on separate

colonies. Collar with minute internal teeth.

Variation. The hydrothecae differ in shape along the length of the stem, those at

the base being more divergent than the rest. The two marginal teeth may be of

unequal size, the more anterior one being shorter.

Remarks, The pores on the internodes with their surrounding collars have

sometimes being called nematothecae, but there is no proof of the presence

of nematophores. The coenosarc of the stem has been seen to produce an out-

growth reaching to the level of the pore, but not protruding through it. The

pore is probably more comparable to the mamelon of certain Plumulariidae.

Distribution outside South Africa. Circumglobal in south temperate waters:

Australasia, Chile, Falklands, Vema Seamount, Antarctic, Suez. Type locality:

Gulf of St. Vincent, Australia.

Distribution in South Africa. Round coast from Lambert’s Bay on west to

Inhaca on east, never common, littoral to 27 m. 32/18 (1), 33/18 (1), 34/18 (s, D,

34/22 (s), 26/32 (1, s)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 251

Amphisbetia operculata (Linnaeus, 1758)

Fig. 83A—E

Sertularia operculata Linnaeus, 1758: 808. Hincks, 1868: 263, pl. 54. Bale, 1884: 67, pl. 6

(fig. 1), pl. 19 (fig. 3).

Sertularia aperta Allman, 1886: 138, pl. 13 (figs 1-2).

Amphisbetia operculata: Ralph, 1961a: 775, fig. 8i-k. Millard, 1964: 26.

Diagnosis. Stem unfascicled, slender and flexuous, branching and rebranching

dichotomously to form bushy or straggling tufts reaching a maximum height

of 148 mm. No marked distinction into main stem and branches. Hydrothecae

in opposite pairs, one pair to an internode, but nodes only visible in younger

regions; members of a pair not contiguous except in axils of branches. Dicho-

tomous branching in a plane at right angles to hydrothecal pairs.

Hydrotheca tubular, sloping outwards, almost or completely adnate,

with no intrathecal ridge, 0,2-0,3 mm in abcauline height (without teeth)

and 0,11-0,14 mm in marginal diameter. Margin facing upwards, with two

sharply pointed latero-abcauline teeth, of which one is usually longer than the

other.

Gonothecae borne on stem and branches, compressed, pear-shaped in

broad view, smooth, with terminal operculate aperture on a low collar, reaching

2,1 mm in height and 0,9 mm in maximum diameter.

Variation. Although the branching is always dichotomous, one limb of the

dichotomy is often much longer than the other, giving the appearance of a long

main stem with subsidiary branches which divide only once or twice or not at all.

The length and thickness of the internodes may be somewhat greater on the

main axis than on the smaller branches, but the difference is never very marked.

The two rows of hydrothecae may be in the same plane or shifted onto the

anterior surface of the stem.

Distribution. Cosmopolitan. Type locality not specified.

Distribution in South Africa. Common from Liideritz Bay in South West

Africa to Richard’s Bay in Natal, littoral to 100 m. 26/15 (1), 28/16 (s), 32/18

(1, s), 33/17 (s), 33/18 (s), 34/18 (s), 34/19 (s), 35/19 (s), 34/22 (I, s), 33/23 (1),

34/23) (Ss; d), 33/25 (s), 34/25 (Ss), 33/26 (s), 33/27 (s), 32/28 (s), 30/30 (), 29/31

(1, s, h), 28/32 (s).

Genus Calamphora Allman, 1888

Diagnosis. Colony stolonial, with hydrothecae and gonothecae arising direct

from hydrorhiza. Hydrotheca barrel-shaped with four marginal teeth and an

operculum of four triangular valves seated in the bays between the teeth and

meeting in the centre as a pyramid. Hydranth with blind caecum.

Type species: Calamphora parvula Allman, 1888.

One species only from South Africa.

252. ANNALS OF THE SOUTH AFRICAN MUSEUM

AtR,$

BAN

ON ie

Fig. 83.

Amphisbetia operculata. A, stem; B, part of stem with female gonophores; C and D,

hydrothecae; E, margin of hydrotheca with operculum.

Calamphora campanulata. F, three hydrothecae, two containing hydranths with blind caecum.

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 253

Calamphora campanulata (Warren, 1908)

Fig. 83F

Sertularella campanulata Warren, 1908: 300, pl. 47 (figs 21-22).

Calamphora campanulata: Stechow, 19196: 83. Stechow, 1925b: 225. Mammen, 1965a: 35,

fig. 67.

Diagnosis. Colony creeping on weeds. Hydrotheca solitary, pedicellate. Pedicel

usually shorter than hydrotheca, spirally twisted, with 2—5 turns, arising at an

angle from hydrorhiza. Hydrotheca terminal, small, barrel-shaped, with 5-8

transverse annulations, 0,4-0,5 mm in height, 0,2-0,3 mm in maximum diameter

and 0,14-0,2 mm in marginal diameter. No internal teeth. Hydranth with

about 20 tentacles.

Gonotheca (not reported from South Africa) borne on hydrorhiza,

pedicellate, barrel-shaped, broader than hydrotheca, transversely annulated,

with operculum of four valves. (Mammen.)

Remarks. Although this is a stolonial species there is some bilateral symmetry.

The blind caecum, which is normally abcauline in the Sertulariidae, is on the

side closest to the hydrorhiza, and the hydropore is excentric and displaced

towards the same side. The perisarc tends to be thicker on the opposite side.

Distribution outside South Africa. Madagascar, India, Indo-China, Japan,

Australia. Type locality: Natal, South Africa.

Distribution in South Africa. Northern Transkei and southern Natal, littoral.

31/30 (1), 30/30 (1)

Genus Crateritheca Stechow, 1921

Diagnosis. Stem erect, unfascicled, pinnate. Stem and hydrocladia bearing

two or more longitudinal rows of hydrothecae.

Hydrotheca sessile, with more than four marginal teeth, with prominent

intrathecal septa and often with external longitudinal ridges. Operculum

reduced; either absent altogether, or consisting of a single membranous valve.

Hydranth with abcauline blind caecum.

Type species: Pericladium novaezelandiae Thompson, 1879.

One species only from South Africa.

Crateritheca acanthostoma (Bale, 1882)

Fig. 84

?Dynamena pluridentata Kirchenpauer, 1864: 14, fig. 10.

Sertularia acanthostoma Bale, 1882: 11, pl. 12 (fig. 4). Bale, 1884: 85, pl. 4 (figs 7-8). Warren

1908: 303, fig. 7, pl. 46 (figs 23-26).

Crateritheca acanthostoma: Millard, 1964: 26, fig. 7.

Diagnosis. Stem moderately stiff, unbranched, reaching 50 mm in height;

divided by transverse nodes into regular internodes, each bearing a pair of

254 ANNALS OF THE SOUTH AFRICAN MUSEUM

opposite hydrothecae, and every third one a pair of opposite hydrocladia

from the proximal region. The two rows of hydrocladia in one plane. Hydro-

cladium divided into internodes of which the first is short and athecate, the

second bears one hydrotheca on the lower surface, and the rest bear a pair of

subopposite hydrothecae each. The two rows of hydrothecae in one plane.

Hydrotheca adnate for a little over half adcauline height, widening evenly

to mouth, straight or bent slightly outwards, 0,2-0,3 mm in abcauline height

and 0,16-0,2 mm in marginal diameter. Margin with eight pairs of teeth, of

which numbers 1, 3, 5, and 7 (counting from the abcauline surface) are short

and bent inwards, numbers 2, 4 and 6 are long and directed slightly outwards,

and number 8 is short and straight. Three intrathecal septa present: a trans-

verse shelf about half-way up adcauline side, a transverse perforated shelf about

one-quarter of the way up abcauline side, and a very narrow transverse shelf

about three-quarters of the way up abcauline side forming the base of a longi-

tudinal trough communicating with the cavity of the hydrotheca. External

surface smooth and without longitudinal ridges or furrows. Hydropore funnel-

shaped. Operculum a delicate membranous plate, present only in young hydro-

thecae. Hydranth with 23 tentacles. Hydrotheca lined with a thin layer of

ectoderm which continues into the abcauline trough where it bears a cluster of

large nematocysts.

Gonotheca (not recorded from South Africa) long, obovate, smooth,

with wide operculate distal aperture.

Variation. In the basal part of the stem there may be two to six athecate inter-

nodes of irregular length and one to four pairs of hydrothecae before the

hydrocladia commence. The hydrocladia normally arise from every third inter-

node, but at times any number from one to six pairs of hydrothecae may be

present between two consecutive pairs of hydrocladia. The hydrocladia

occasionally branch in the same manner as the stem.

Distribution outside South Africa. Australia (type locality), Madagascar.

Distribution in South Africa. Natal coast, littoral to 34 m. 31/29 (s), 31/30 (1),

30/30(1), 29/31 (1), 28/32 (s)

Genus Dictyocladium Allman, 1888

Diagnosis. Stem erect, branched or unbranched. Hydrothecae in opposite or

subopposite pairs, alternate pairs staggered in at least some regions of stem

to give the appearance of four longitudinal rows. Hydrotheca sessile, with three

or four marginal teeth and an operculum with a corresponding number of valves.

Hydranth with no abcauline caecum.

Type species: Dictyocladium dichotomum Allman, 1888.

One species only from South Africa.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 255

Fig. 84.

Crateritheca acanthostoma. A, hydrotheca in side view, adcauline side on right; B, stem;

C, part of stem with origins of hydrocladia; D, hydrotheca viewed from above, showing

marginal teeth, the aperture closed by operculum; E, t.s. abcauline wall viewed from

above, showing upper abcauline septum (c); F, t.s. hydrotheca at deeper level viewed

from above, showing adcauline septum (a) and lower abcauline septum ()).

Scale: B in cm, the rest in mm/10.

256 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dictyocladium coactum Stechow, 1923

Fig. 86F—H

Dictyocladium coactum Stechow, 19236: 107. Stechow, 1925a: 466, fig. 27. Millard, 1957: 206.

Diagnosis. Hydrorhiza attached to substratum at intervals only. Stem flexuous,

unfascicled, normally unbranched, reaching 28 mm in height, with nodes at

irregular intervals and a varying number of hydrothecae to a node. Hydro-

thecae alternate to opposite, alternate pairs typically staggered to give four

longitudinal rows. Stem narrowed and devoid of hydrothecae in region of

nodes.

Hydrotheca sunk into stem for all, or almost all, adcauline length, curved

outwards, with distinct bulge in lower part of abcauline wall, 0,2-0,4 mm in

abcauline height and 0,16—0,2 mm in marginal diameter. Margin with four low,

but distinct, teeth. Operculum of four triangular valves seated in the bays

between the marginal teeth and meeting in the centre as a pyramid.

Gonothecae borne on the stem on the proximal parts of the internodes,

ovate, deeply annulated throughout or in distal part only, with terminal aper-

ture but no collar.

Variation. Branching stems occur rarely, the branches arising from within

hydrothecae and exactly resembling the stem. Stolonization is not so profuse

as in the type species of the genus and only occasionally do the terminal ends of

the stems form stolons which attach to the substratum.

The arrangement of the hydrothecae on the stem is very variable. The

number to an internode varies and so does the number of longitudinal rows.

Usually there are two longitudinal rows in the lower region formed by alternate,

subopposite or opposite pairs of hydrothecae, changing to four longitudinal

rows of tightly packed hydrothecae in the upper part. In one case five

longitudinal rows were seen, three on one side and two on the other. Often

there are two longitudinal rows at the base of an internode and four at the distal

end. Occasional stems have two rows throughout. Along the length of the stem

there is a change in the shape of the hydrotheca, the proximal ones being

strongly bent outwards with their margins almost parallel to the axis of the

stem, and the distal ones less so. The bulge on the abcauline wall of the hydro-

theca varies in degree, sometimes it is very marked and there is a transverse

groove immediately above it. Isolated hydrothecae in a colony may have an

abcauline internal tooth which may be very large.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank.

Distribution in South Africa. South coast, from False Bay to Natal in 0-155 m.

34/18 (s), 34/19 (s), 35/22 (d), 34/24 (d), 34/25 (s), 33/26 (d), 33/27 (s), 32/28 (s),

29/31 (s), 28/32 (s)

Genus Diphasia L. Agassiz, 1862

Syn. Nigellastrum Oken, 1815.

Diphasiella Stechow, 1921.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA Za

Diagnosis. Stem erect, branched or unbranched, fascicled or unfascicled.

Stem and hydrocladia bearing a double, or rarely a triple, row of hydrothecae.

Hydrotheca sessile, tubular and usually expanding distally, usually without

marginal teeth, with an operculum of one large adcauline valve. Hydranth

without abcauline caecum. Gonothecae unprotected, usually dioecious and

provided with projecting ridges or spines, with marsupium in female.

Type species: Sertularia rosacea Linnaeus, 1758.

KEY TO SPECIES

(Doubtful species not included; for these see p. 260)

1. Hydrotheca with four small marginal teeth pet: ee at D. tetraglochina

— Hydrotheca with no marginal teeth he a m3 S ot Bs Be pte 2

2. Hydrotheca with abcauline intrathecal septum .. fs me iP D. heurteli

— Hydrotheca without intrathecal septum .. ay: is bi se D. digitalis

Diphasia digitalis (Busk, 1852)

Fig. 85E

Sertularia digitalis Busk, 1852: 393.

Nigellastrum digitale: Mammen, 1965a: 57, fig. 89.

Diphasia digitalis: Vervoort, 1968: 37, fig. 17. Millard & Bouillon, 1973: 67, fig. 9A. Millard

& Bouillon, 1974: 31, fig. 6B.

Diagnosis. Stem stiff, unfascicled, branched or unbranched, reaching a maxi-

mum height of 44 mm; with transverse nodes visible in younger regions only,

each internode bearing a pair of hydrothecae; a hinge-joint present near base

below first pair of hydrothecae. Hydrocladia alternate, arising from postero-

lateral surface of stem usually after every two pairs of hydrothecae and forming

almost a right angle with stem, the two rows in one plane. Hydrothecae in

opposite pairs, consecutive pairs close, separated from one another by a distance

of less than ¢ height or overlapping. In lower region of stem members of a pair

of hydrothecae placed on lateral surfaces, not contiguous with one another,

and adnate to stem for about 3 height; in distal region and on hydrocladia

members of a pair placed on anterior surface, contiguous with one another

and adnate for up to entire length.

Hydrotheca tubular, widening gently to margin, smoothly curved outwards,

usually polygonal in section with 3-5 angles which are visible in front view as

longitudinal ridges, perisarc thickened on abcauline wall, 0,7—1,0 mm in abcau-

line height and 0,3 mm in marginal diameter. Margin untoothed, saddle-shaped.

Gonothecae (not reported from South Africa) borne on stem, elongate,

covered with short, curved spines arranged in 10-16 longitudinal rows.

Variation. Regeneration of the hydrotheca is often indicated by the persistence

of an old operculum below the new one, although the old margin seldom

leaves a regeneration line.

The variation in the hydrothecae along the length of the stem is

characteristic of the species and is indicated in the diagnosis.

258 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. Circumglobal in tropical and subtropical

waters. Type locality: Torres Straits.

Distribution in South Africa. Inhaca only. 26/32 (s)

Diphasia heurteli Billard, 1924

Fig. 85A-D

Diphasia pinaster: Billard, 1907a: 357.

Diphasia heurteli Billard, 1924: 67, fig. 2.

Diphasia heurteli var. simplex Billard, 1933: 19, fig. 7.

non Diphasia heurteli: Nutting, 1927: 218, pl. 42 (figs 5-7).

Diagnosis. Stem fairly stiff, unfascicled, unbranched or, rarely, with one

lateral branch, reaching a maximum height of 27 mm, with a basal athecate part

terminated by an oblique hinge-joint, the remainder bearing hydrothecae in

strictly opposite pairs. Consecutive pairs of hydrothecae separated by slightly

oblique nodes in some regions only, pairs close to one another and often over-

lapping. Members of a pair not in contact with one another.

Hydrotheca tubular, widening to margin, curved outwards, flattened on

abcauline side in basal region and with the angles of this flat surface continued

as two longitudinal ridges almost to margin, three other longitudinal ridges

present but less distinct, one abcauline and two latero-adcauline; adnate for

isi Of adcauline side, 0,4-0,7 mm in abcauline height and 0,16-0,3 mm in

marginal diameter. Abcauline wall thickened and an abcauline intrathecal

septum usually present, well developed and curved distally, the base forming a

crescent-shaped figure when viewed externally. Margin untoothed, facing

upwards and almost perpendicular to stem.

Female gonothecae borne in a single row on front of stem, arising

immediately below hydrothecae on one side, saccular, with wide distal aperture,

bearing irregularly arranged short, blunt spines on distal half, containing many

small eggs. Male gonothecae unknown.

Variation. In the younger regions and sometimes in complete young stems

the intrathecal septum may be absent as in var. simplex Billard, 1933. The

abcauline wall of the hydrotheca is, however, thickened in this region.

In addition to the normal operculum many hydrothecae have one or two

supplementary opercula hinged to the adcauline wall just below the level of the

intrathecal septum.

Remarks. This is the first discovery of the gonothecae of D. heurteli in the type

area. Gonothecae of material from the China Sea attributed to D. heurteli

were described by Nutting (1927). These are completely different in structure,

and I must therefore exclude Nutting’s material from the synonymy.

D. heurteli is very similar to D. mutulata, a species well illustrated by

Billard (1933). The main differences are the shorter free part of the hydrotheca

in the latter, and the structure of the gonotheca which in D. mutulata has a

narrow distal aperture.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 259

B=) EG

Fig. 85.

Diphasia heurteli. A, stems; B, part of stem (some hydrothecae with supplementary opercula);

C, hydrotheca; D, gonotheca.

Diphasia digitalis. E, unbranched stem.

Diphasia tetraglochina. F, stem; G, gonotheca; H, a pair of hydrothecae viewed from above

to show asymmetry (operculum in position on right).

Scale: A in cm, the rest in mm/10.

260 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. Mocgambique (type locality), Gulf of Suez.

Distribution in South Africa. Natal to Mocgambique, 2-100 m, rare. 29/31 (s),

28/32 (d), 24/35 (s)

Diphasia tetraglochina Billard, 1907

Fig. 85F—H

Diphasia tetraglochina Billard, 1907a: 358, fig. 7. Millard, 1964: 28, fig. 8. Millard & Bouillon,

1974: 31, fig. 6C.

Diagnosis. Hydrorhiza creeping on weed, with internal thickenings of perisarc.

Stem short, reaching a maximum height of 7 mm, unfascicled, unbranched,

divided by markedly oblique nodes into internodes each bearing a pair of opposite

hydrothecae. Members of a pair separate in front, sometimes contiguous behind

in distal region of stem.

Hydrotheca tubular, widening to margin, curved outwards, not bilaterally

symmetrical but twisted towards anterior surface, adnate for 4-3? length,

0,3-0,5 mm in abcauline length and 0,15—0,3 mm in marginal diameter. Margin

with four small, pointed teeth, one adcauline, two abcauline and one anterior.

Gonothecae borne on stem, one to each, below first pair of hydrothecae,

elongate-oval, bearing small spines in distal half, reaching 0,8 mm in length

and 0,5 mm in maximum diameter. Aperture terminal, small, circular, on a

raised neck.

Variation. The distal region of the stem normally has longer internodes and

larger hydrothecae than the proximal region. The perisarc is sometimes thickened

in the centre of the abcauline thecal wall and occasionally around the margin.

Distribution outside South Africa. Madagascar only. Type locality: Fort

Dauphin.

Distribution in South Africa. Two areas only: Agulhas Bank south of East

London, and Inhaca district. 33/27, 25/32, 26/32 (s)

Doubtful species

Diphasia attenuata (Hincks, 1866)

Sertularia rosacea: Busk, 1851: 118.

Diphasia attenuata: Hincks, 1868: 247, pl. 49 (fig. 1a—d). Vervoort, 1959: 258, fig. 26. Millard,

1961: 204.

non Sertularia rosacea Linnaeus, 1758: 807.

Remarks. Busk reported this species from Algoa Bay as Sertularia rosacea (see Millard

1961). It has not been reported since and the record must be regarded as doubtful.

Diphasia bipinnata Allman, 1886

Diphasia bipinnata Allman, 1886: 136, pl. 12 (figs 1-2).

Remarks. Allman was doubtful about the locality of the material on which this species

was founded, giving it as ‘Cape of Good Hope’. The species has never been recorded

again, and from Allman’s description and figures it might well be a synonym for the

well-known Diphasia fallax (Johnston 1847).

MONOGRAPH ON,THE HYDROIDA OF SOUTHERN AFRICA 261

Diphasia nigra (Pallas, 1766)

Sertularia nigra Pallas, 1766: 135. Busk, 1851: 118.

Sertularia pinnata Pallas, 1766: 136.

Diphasia pinnata: Hincks, 1868: 255, pl. 52. Vervoort, 1946a: 232, fig. 100.

Remarks. For this species there is only Busk’s record of 1851. Since it has hot been

reported from South Africa since, the record must be regarded as doubtful.

Genus Dynamena Lamouroux, 1812

Syn. Pasythea Lamouroux, 1812.

Pasya Stechow, 1922.

Diagnosis. Stem erect, branched or unbranched. Stem and branches bearing

hydrothecae in two longitudinal rows. Hydrothecae in opposite or subopposite

pairs, which are often concentrated in groups. Hydrotheca sessile, partly or

completely adnate, with two marginal teeth seated more or less midway between

adcauline and abcauline edge, and usually a small, median adcauline one.

Operculum of two valves, a smaller adcauline one and a larger abcauline one,

the former often divided into two by a median partition. Hydranth with no

abcauline caecum.

Type species: Sertularia pumila Linnaeus, 1758.

KEY TO SPECIES

(Doubtful species not included; for these see p. 268)

i Hydrothecae on simple stems and on hydrocladia of branching stems in subopposite

pairs. Members of a pair never contiguous .. : D. crisioides

— Hydrothecae on simple stems and on hydrocladia of branching syne always in ae

opposite pairs. Members of at least some pairs contiguous ee Zz

2. Hydrotheca tubular and not narrowing to mouth. Hydrothecae on ans stems a

on hydrocladia of branching stems never grouped, with only one pair to an internode

D. cornicina

— Hydrotheca narrowing to mouth. Stem never branched. Hydrothecae often grouped,

with two or more pairs to an internode we

3. Hydrotheca sac-shaped, with greatest width more than half Spandine height D. obliqua

— Hydrotheca tubular but bulging at base of abcauline side, with greatest width half

or less than half abcauline height .. ci e f ee .. D. quadridentata

Dynamena cornicina McCrady, 1858

Fig. 86A—-E

Dynamena cornicina McCrady, 1858: 102. Billard, 1925a: 188, tig. 40, pl. 7 (fig. 23). Vervoort,

1941: 206, fig. 3. Millard, 1964: 29, fig. 9.

Diagnosis. Stem unfascicled, either simple or pinnately branched.

Branching stem reaching 60 mm, divided by straight nodes into regular

internodes, each bearing one hydrocladium and three hydrothecae (one in axil

and a subopposite or alternate pair above). Hydrocladia alternate, the two rows

in one plane. Hydrocladium arising from short apophysis, with one basal

athecate internode terminated by a hinge-joint, and a series of thecate inter-

nodes each bearing a pair of opposite hydrothecae. Members of a pair of

262 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 86.

Dynamena cornicina. A, colony with simple and branched stems; B, margin of hydrotheca with

operculum (abcauline valve in broken line); C and D, the upper two and the lower two

pairs of hydrothecae of a simple stem bearing 12 pairs in all; E, gonotheca.

Dictyocladium coactum. F and G; hydrothecae, G with an internal tooth; H, part of colony

with two stems and gonothecae.

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 263

hydrocladial hydrothecae always contiguous in front, separate behind, placed

on upper surface of hydrocladium.

Simple stem reaching a height of 9 mm. Basal athecate part terminated by

oblique hinge-joint. Remainder with transverse or slightly oblique nodes.

Each internode bearing one pair of opposite hydrothecae. Hydrothecae not

grouped. Members of a pair of hydrothecae contiguous in front (except some-

times in proximal region of stem), separate behind.

Hydrotheca tubular and of more or less equal diameter throughout;

adnate for over half adcauline length, then curved outwards, 0,2-0,5 mm in

abcauline height and 0,13-0,20 mm in marginal diameter, abcauline wall

thickened below margin. Lateral marginal teeth large, delicate, triangular.

Adcauline marginal tooth small.

Gonotheca arising from hydrorhiza or occasionally from base of stem,

ovate, deeply annulated, with broad aperture and flat operculum, reaching

1,4 mm in length and 0,9 mm in maximum diameter

Variation. In South African material the stem internodes (in simple stems)

or hydrocladial internodes (in pinnate stems) are regular and short, with the

interval between consecutive pairs of hydrothecae less than the hydrothecal

length, but in other localities the internode length is reported as variable, and

the interval between consecutive pairs of hydrothecae may exceed the hydro-

thecal length.

A change in shape of the hydrotheca takes place along the length of the

simple stem and hydrocladium of pinnate stems, those at the base being shorter,

less adnate and more markedly bent out than the distal ones. The axillary

hydrothecae are less adnate and more sharply curved out than the rest.

Distribution. Cosmopolitan. Type locality: Charleston harbour.

Distribution in South Africa. Port Elizabeth to Inhaca, littoral to 14 m. 33/25

(s), 34/25 (s), 31/29 (1), 26/32 C, s), 25/32, 21/35

Dynamena crisioides Lamouroux, 1824

Fig. 87A—F

Dynamena crisoides Lamouroux, 1824: 613, pl. 90 (figs 11-12). Billard, 1925a (including all

varieties): 181, figs 36-39, pl. 7 (figs 21-23), pl. 8 (fig. 24). Millard, 1968 (including var.

gigantea): 183, fig. 6C. Mammen, 1965a: 51, figs 84-85. Vervoort, 1968: 38, fig. 18.

Millard & Bouillon, 1974: 32, fig. 6D.

Thuiaria tubuliformis: Warren, 1908: 314, fig. 12.

Thuiaria interrupta: Gravely, 1927: 13, pl. 2 (figs 7, 12).

Diagnosis. Stem unfascicled, straight or zigzag, reaching a maximum height of

160 mm, bearing alternate hydrocladia; with a short basal athecate part termi-

nated by a transverse node, then thecate internodes separated by transverse or

slightly oblique nodes, each internode normally bearing one hydrocladium near

base, one hydrotheca in the axil and a variable number of subopposite pairs

of hydrothecae above. Hydrocladium borne on long apophysis, which may be

264 ANNALS OF THE SOUTH AFRICAN MUSEUM

separated from the stem by a partial or complete node, divided by straight

nodes into internodes which bear a variable number of subopposite pairs of

hydrothecae. The two rows of hydrothecae in one plane; members of a pair not

contiguous with each other, though consecutive pairs on an internode may

overlap to form groups.

Hydrotheca tubular, adnate for half to over nine-tenths of adcauline length,

then bent outwards, 0,3-0,7 mm in abcauline height and 0,09-0,2 mm in mar-

ginal diameter. Margin facing outwards, parallel to axis or nearly so, with two

broad and triangular lateral marginal teeth and one smaller adcauline one.

Hydranth with about 19 tentacles.

Gonotheca arising from stem or branch below hydrotheca, occasionally

from within hydrotheca, smooth or irregularly folded, ovate, with curved distal

neck and operculum.

Variation. This is a very variable species, and a number of varieties and forms

are on record. It does not seem practicable to use subspecific rank for these,

since in many cases intermediate forms are known (Billard 1925a; Gravely

1927; Mammen 1965a). Several occur in South Africa.

The normal form typically has a short (about 20 mm), zigzag stem which

is narrow at the base (0,4 mm or less), so that members of a pair of hydro-

thecae are separated by a distance less than the diameter of one of them.

Forma gigantea Billard, 1925 has a taller (100-160 mm) stem, which

is straight except for the extremity and is much wider at the base (0,5-0,9 mm)

so that members of a pair of hydrothecae are separated by a distance at least

equal to, and usually considerably greater than, the diameter of one of

them.

Forma alternata Billard, 1925 shows no grouping of the hydrothecae on

the hydrocladium, but has only one subopposite pair to each internode. The

hydrotheca is smaller and less adnate than in the typical form (half to two-

thirds as against two-thirds or more) and the hydrocladial apophysis arises

below the third hydrotheca on each normal stem internode.

Billard (1925a) also distinguishes a var. peculiaris with internal teeth in some

hydrothecae, either one adcauline or one abcauline or both. In South Africa

internal teeth may occur in certain hydrothecae of any of the above forms,

though never in the whole colony.

All the forms show variation in the number of hydrothecae to an inter-

node; the usual number on the stem is three, but there may be more or less;

on the hydrocladia the number varies from two to ten. The number of

hydrocladia to a stem internode may vary from nought to two.

Distribution outside South Africa. Cosmopolitan, mainly in tropical and

subtropical waters. Type locality: Moluccas.

Distribution in South Africa. East coast, from the Haven northwards, littoral.

32/28 (I), 31/29 (1), 31/30 (1), 30/30 @); 29/31 (1), 26/32 (), 25/32, 23/35 Ms 235

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 265

Fig. 87.

Dynamena crisioides. A, gonothecae: B, part of stem of normal form with origins of hydro-

cladia; C, hydrocladium of normal form; D, hydrocladium of forma alternata; E,

hydrocladium of forma gigantea; F, stems of normal form (left) and forma alternata

(right).

Dynamena quadridentata. G, gonotheca; H, unusual stem with most of the hydrothecal pairs

ungrouped; J, typical stem.

Scale: F in cm, the rest in mm/10.

266 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dynamena obliqua Lamouroux, 1816

Fig. 88F—G

Dynamena obliqua Lamouroux, 1816: 179. Billard, 1925a: 198. Millard, 1958: 184, fig. 6A.

Hirohito, 1969: 19, fig. 13.

Pasythea quadridentata var. Balei Billard, 1907a: 355, fig. 6.

Diagnosis. Hydrorhiza with or without internal perisarcal thickenings. Stem

unfascicled, unbranched, reaching a maximum height of 17 mm. Normal

nodes indistinct. Oblique hinge-joints present (a) terminating basal athecate

part of stem, and (6) at irregular intervals in distal region, each forming the

termination of a separate, narrow, athecate internode. Each thecate internode

usually bearing only one pair of opposite hydrothecae, rarely a group of two

pairs contiguous with each other. Members of a pair of hydrothecae contiguous

in front (except in basal region of stem), separate behind.

Hydrothecae swollen but narrowing to mouth, bent outwards, adnate for

over half adcauline length, 0,2-0,3 mm in abcauline height and 0,12-0,14 mm

in marginal diameter, aperture directed obliquely forwards. Lateral marginal

teeth broad, triangular, sharp or bluntly rounded. Adcauline marginal tooth

distinct.

Gonotheca (not reported from South Africa) borne on front of stem near

base, barrel-shaped, with four or more transverse annulations, with a broad

distal aperture on a low neck and a flat operculum.

Variation. In this species there is less tendency towards grouping of thecal pairs

than, for instance, in D. quadridentata, and many stems bear only one pair per

internode throughout. In South Africa no more than two pairs have been

observed on an internode, although as many as four have been observed else-

where.

Internal teeth occasionally occur in some hydrothecae of a stem, and there

may be one abcauline and one adcauline, or one abcauline and two latero-

adcauline, or one adcauline and two latero-abcauline teeth.

Distribution outside South Africa. Australasia (type locality), Japan,

Mogambique.

Distribution in South Africa. Natal and Inhaca, 10-66 mm. 30/30°(s), 29/31

(s), 26/32 (s)

Dynamena quadridentata (Ellis & Solander, 1786)

Fig. 87G—J

Sertularia quadridentata Ellis & Solander, 1786: 57, pl. 5 (fig. g, G).

Pasythea quadridentata: Warren, 1908: 312, fig. 11.

Dynamena quadridentata: Billard, 1925a: 194, figs 42-43. Millard, 1958: 186, fig. 6B. Vervoort

1968: 41, fig. 19.

Dynamena gibbosa: Billard, 1925a: 199, fig. 45.

Diagnosis. Hydrohiza creeping on weed, commonly with internal perisarcal

thickenings. Stem unfascicled, unbranched, reaching a maximum height of

MONOGR4APH ON THE HYDROIDA OF SOUTHERN AFRICA 267

Fig. 88.

Idiellana pristis. A, stem: B, part of stem in anterior view with origins of hydrocladia; Cand

D, lateral and abcauline views of operculum; E, hydrothecae.

Dynamena obliqua. F, upper part of stem; G, complete stem.

Scale: A in cm, the rest in mm/10.

268 ANNALS OF THE SOUTH AFRICAN MUSEUM

7 mm. Normal nodes transverse and often indistinct. Oblique hinge-joints

present (a) terminating basal athecate part of stem, and (6) at irregular intervals

in distal region, each forming the termination of a separate, narrow, athecate

internode. Each thecate internode bearing one or a group of pairs of opposite

hydrothecae; the pairs in a group up to four in number, contiguous with one

another and showing a difference in shape, the proximal pair being more diver-

gent and less adnate than the distal one. Members of a pair of hydrothecae

contiguous in front, separate behind.

Hydrotheca tubular but narrowing to margin, bent outwards, adnate for

over half adcauline length, 0,17-0,4 mm in abcauline height and 0,07-0,13 mm

in marginal diameter, with or without internal teeth; members of solitary pairs

and the basal pair of a group with a distinct outward bulge in base of abcauline

wall. Lateral marginal teeth broad and triangular. Adcauline marginal tooth

small but distinct.

Gonotheca borne on front of stem at base of first thecate internode,

barrel-shaped, with 3-6 distinct transverse annulations, with broad distal

aperture and flat operculum.

Variation. In this species there is a greater tendency towards grouping of

hydrothecal pairs than in D. obliqua, and single pairs are rare and usually occur

only in the proximal region of the stem. Hinge-joints are more common than in

D. obliqua.

The presence of internal thecal teeth is a variable character and there may

be one adcauline and one or two abcauline ones.

In the literature a number of varieties of this species has been described

which tend to grade into one another. The South African material appears to

be intermediate between var. nodosa Hargitt, 1908, and Dynamena gibbosa

Billard, 1924, which is considered to merit varietal rank only. Both are dis-

tinguished by an outward bulge in the abcauline wall of the basal hydrotheca of

a group, more distinct in v. gibbosa than in v. nodosa.

Distribution outside South Africa. Circumglobal in tropical and warm temperate

waters. Type locality: west coast of Africa near Ascension Island.

Distribution in South Africa. Port St. Johns to Mocambique, littoral to 49 m.

31/29 (s), 30/30 (1), 29/31 ( s), 27/32.(), 26/32 (, s),-25/32, 24/35) Gs 237s

21/35

Doubtful species

Dynamena pumila (Linnaeus, 1758)

Sertularia pumila Linnaeus, 1758: 807. Hincks, 1868: 260, pl. 53 (fig. 1).

Dynamena pumila: Krauss, 1837: 28. Calder, 1970a: 1528, pl. 6 (fig. 1).

Remarks. This species has been reported once only, by Krauss, from Mossel Bay. No

diagrams are given and the identification is dubious.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 269

Genus Hydrallmania Hincks, 1868

Diagnosis. Stem erect, giving off spirally arranged branches. Branches pinnate,

bearing alternate hydrocladia. Hydrocladium in mature colony bearing hydro-

thecae in one longitudinal row, their distal ends directed alternately to left and

right. Hydrotheca sessile, usually partly adnate, with two lateral and often ill-

defined marginal teeth. Operculum of two delicate valves, a larger adcauline

one and a smaller abcauline one which is not easily recognizable. Hydranth

with abcauline blind caecum.

Type species: Sertularia falcata Linnaeus, 1758.

A doubtful record of one species only in South Africa.

Doubtful species

Hydrallmania falcata (Linnaeus 1758)

Sertularia falcata Linnaeus, 1758: 810

Plumularia falcata: Busk, 1851: 118

Hydrallmania falcata: Broch, 1918: 135, fig. 73. Millard, 1961: 206.

Remarks. This species occurs exclusively in the North Atlantic. Busk’s record from

South Africa must be regarded as doubtful although his material was correctly identi-

fied (Millard 1961). It has never again been reported from this country.

Genus I/diellana Cotton & Godfrey, 1942

Syn. Idiella Stechow, 1919.

Idia Lamouroux, 1816.

Diagnosis. Upright colonies with pinnate stems bearing alternate hydrocladia.

Stem and hydrocladia bearing a double series of alternate or subalternate

hydrothecae on anterior surface. Hydrotheca sessile, with two poorly developed

lateral lobes. Operculum of one adcauline valve. Hydranth with no abcauline

caecum.

Type species: Jdia pristis Lamouroux, 1816.

One species only from South Africa.

Idiellana pristis (Lamouroux, 1816)

Fig. 88A—E

Idia pristis Lamouroux, 1816: 199, pl. 5 (fig. 5). Allman, 1888: 85, pl. 39 (figs 1-10). Ritchie

1910b: 820.

Idiellana pristis: Ralph, 1961a: 766, fig. 5c-e.

Diagnosis. Stem unfascicled, reaching 60 mm in height, divided into regular

internodes by oblique nodes which slope in alternate directions; each internode

bearing one hydrocladial apophysis and three hydrothecae (one in axil and an

alternate pair above); the two rows of hydrothecae not contiguous. Hydro-

cladium unsegmented or with a few sparse nodes at long intervals, bearing a

double row of alternate, overlapping hydrothecae on the anterior face, the two

rows contiguous with one another.

270 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hydrothecae tubular, adnate for over half length, then free and bent out

at a wide angle, 0,4-0,6 mm in abcauline height, and 0,13-0,20 mm in marginal

diameter. Margin with two broadly triangular lateral lobes; rotated to face

distally and posteriorly. No internal teeth. Operculum not sharply demarcated

from hydrotheca at adcauline edge, with a median ridge dividing it into two

for part of its length.

Gonotheca (not reported from South Africa) borne on front of stem below

hydrotheca, urn-shaped, longitudinally ridged, with short pedicel and circular

distal aperture on a raised tubular collar.

Remarks and variation. The broad hydrocladia with their double row of pro-

jecting hydrothecae resemble the rostrum of the saw-fish, Pristis, after which

the species was named. The overlapping of the hydrothecae gives the impression

of a division of the hydrocladium into a double series of chambers. Rejuvena-

tion of the margin of the hydrotheca is common, resulting in variation in length

of the free part. Axillary hydrothecae on the stem are less bent outwards than

the others. A longitudinal ridge is sometimes visible on the anterior surface of

the hydrotheca.

The hydrotheca is commonly described as having a median adcauline

marginal tooth, but there is no sign of this in the South African material.

The operculum in fact is continuous with the adcauline edge as described by

Ritchie (19106) and there is no hinge. It opens by bending and in old hydrothecae

tends to collapse into the cavity.

Distribution outside South Africa. Circumglobal in tropical seas, extending into

temperate waters in certain areas. Type locality: New Holland (Australasia).

Distribution in South Africa. East coast: Natal and Mocambique, 0-44 m.

30/30'(S); 26/3221); 25/32 G), 21/35

Genus Parascyphus Ritchie, 1911

Diagnosis. Stem erect, unbranched or little branched, bearing two rows of

alternate hydrothecae. Hydrotheca pedicellate and free from stem, elongated,

bilaterally symmetrical. Margin with three or four teeth. Operculum pyramid-

shaped, of three or four valves. Diaphragm small or incomplete. Hydranth with

abcauline caecum.

Type species: Laomedea simplex Lamouroux, 1816.

One species only from South Africa.

Parascyphus simplex (Lamouroux, 1816)

Fig. 89A-B

Laomedea simplex Lamouroux, 1816: 206.

Thyroscyphus simplex: Bale, 1915: 245.

Parascyphus simplex: Splettstésser, 1929: 100, 126, figs 92-94. Millard, 1968: 268, fig. 4D.

Diagnosis. Stem stiff, unfascicled. unbranched or sparsely branched, reaching

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 274

12 mm in height. The two rows of hydrothecae more or less in one plane.

Stem and hydrocladia divided into internodes by slightly oblique nodes, each

internode bearing a hydrotheca on an apophysis near the distal end.

Hydrothecal pedicel short, a little narrower than apophysis, not annulated,

separated from apophysis by a partial or complete node. Hydrotheca small to

medium, elongate, markedly convex on adcauline side, straight or with a double

curvature on abcauline side, 0,5-0,6 mm in height from diaphragm and 0,19-

0,2 mm in marginal diameter. Margin with three tall pointed teeth, one adcau-

line and two latero-abcauline, separated by deep bays. Operculum of three

valves. Diaphragm present on adcauline side only.

Gonothecae (not recorded from South Africa) borne on lower part of

stem, elongate-oval, smooth, with rounded distal end and small circular aperture

(Bale 1915).

Variation. The rim of the hydrotheca may be thickened to a varying degree.

Stolonization may occur.

Distribution outside South Africa. Australasia (type locality), Scotland, Gough

Island, Vema Seamount (South Atlantic).

Distribution in South Africa. One record only, from the Natal coast in 91 m.

30/31 (s)

Genus Salacia Lamouroux, 1816

Syn. Dymella Stechow, 1922.

Diagnosis. Stem erect, bearing hydrothecae in two longitudinal rows, with or

without hydrocladia which may be opposite or alternate. When present, hydro-

cladia different in structure to stem, with internodes of irregular length. Hydro-

theca sessile, partly or completely adnate, without distinct marginal teeth.

Aperture triangular. Operculum of one large, abcauline valve. Hydranth without

abcauline caecum.

Type species: Salacia tetracythara Lamouroux, 1816.

Remarks. The conclusions of Billard (1925a: 137) on the validity and nature

of this genus have been adopted.

KEY TO SPECIES

. Stem without hydrocladia, bearing opposite pairs of ers one pair to an inter-

node ae ae S. desmoides

Stem bearing Doporite hydrocladia. Sridrothecaen in groups, more than one pair to an

internode on stem and hydrocladia a a be Ne: sie a fhe

. Hydrocladia arising at right angles to stem. Groups of hydrothecae separated by a

distance greater than the height of one hydrotheca ; S. disjuncta

Hydrocladia arising at an angle of 50-60° to stem. Groups of hydrocladial hydrothecae

separated by a distance less than the height of one hydrotheca oh S. articulata

ey pee ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 89.

Parascyphus simplex. A, part of stem; B, hydrotheca and hydranth.

Salacia articulata. C, fertile stem; D, part of stem with origins of hydrocladia; E, gonotheca;

F, hydrothecae.

Scale: C in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA pe.

Salacia articulata (Pallas, 1766)

Fig. 89C-F

Sertularia articulata Pallas, 1766: 137.

Thuiaria ellisii Busk, 1851: 119.

Thuiaria persocialis Allman, 1876: 271, pl. 17 (figs 4-6).

Thuiaria pectinata Allman, 1888: 69, pl. 33 (figs 1-1a).

Thuiaria articulata: Ritchie, 1909: 84, fig. 6. Broch, 1914: 36, pl. 1 (fig. 3).

Dymella articulata: Vervoort, 19466: 320.

non Thuiaria articulata: Hincks, 1868: 277, pl. 60.

non Dymella articulata: Vervoort, 1946a: 264, fig. 116.

Diagnosis. Stem moderately stiff, unfascicled, unbranched, bearing opposite

hydrocladia, reaching a maximum height of 220 mm but more commonly 40-

80 mm, divided by straight nodes into fairly regular internodes which normally

bear three pairs of opposite hydrothecae and one pair of hydrocladia arising

between the first and second pairs of hydrothecae. Hydrocladia forming a wide

angle with the stem (50-60°), the two rows in one plane. The two rows of

hydrothecae seated on the sides of the stem, and well separated from one

another.

Hydrocladium narrower than stem, with distinct nodes at irregular intervals,

each internode bearing a variable number of subopposite to opposite pairs of

hydrothecae. The two rows of hydrothecae seated on the sides of the hydro-

cladium and not contiguous with one another.

Hydrotheca tubular, curved outwards, adnate for all or almost all adcauline

length, narrowing slightly to margin, 0,2-0,4 mm in abcauline height and 0,11-

0,18 mm in marginal diameter. Margin untoothed, thickened on abcauline edge.

No internal teeth.

Gonothecae borne on stem or hydrocladia, ovoid, smooth or transversely

annulated, truncated distally, with a broad terminal aperture on a low collar,

reaching 3 mm in height and 1,5 mm in maximum diameter.

Variation. Irregularities occasionally occur in the arrangement of the stem inter-

nodes, which may bear but one pair of hydrothecae and no hydrocladia, or

two pairs of hydrothecae and one pair of hydrocladia. In the basal region of

the stem below the first hydrocladium there is a variable number of hydrothecae

to an internode. The interval between successive pairs of hydrothecae also

varies and the pairs tend to be more closely placed on the hydrocladia, where

they may overlap one another, than on the stem, where there is usually a short

interval separating two pairs. Members of a pair of hydrothecae are opposite

on the stem, but subopposite in the proximal regions of the hydrocladia, grad-

ually changing to opposite more distally. Stolonization from the ends of

hydrocladia is common. Rarely branching hydrocladia occur.

Remarks. There has been much confusion in the literature between this species

and S. lonchitis (Ellis & Solander, 1786). The latter has a northern habitat and

can be distinguished by its alternate hydrocladia.

274 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. Vema Seamount (South Atlantic), tropical

South West Africa. Type locality: Atlantic Ocean.

Distribution in South Africa. All round the coast, particularly common in the

south-west area; littoral to 135 m. [19/12()], 26/15 (S), 27/15 @); 32/18 G)

33/17 (s), 33/18 (1), 34/18 (1, s), 34/21 (s), 35/21 (d), 34/22 (s), 34/23 (s), 34/24 (d),

33/25, 34/25 (s), 33/26 (s), 33/27 (1, s), 32/28 (s), 33/28 (Ss), 30/30 (s), 30/31 (s),

29/31 (s), 28/32 (s), 26/33 (d), 24/35 (d)

Salacia desmoides (Torrey, 1902)

Fig. 90A—C

Sertularia desmoidis Torrey, 1902: 65, pl. 8 (figs 70-72).

Sertularia desmoides: Nutting, 1904: 56, pl. 3 (figs 1-3).

Salacia desmoides: Billard, 1924: 66. Millard, 1967: 179, fig. 4A—C.

Diagnosis. Stem unfascicled, usually unbranched, slender, reaching a maximum

height of 4 mm and bearing up to seven pairs of well-spaced opposite hydro-

thecae. Nodes very oblique and resembling hinge-joints; usually one below each

pair of hydrothecae. Members of a pair of hydrothecae contiguous in front,

separate behind.

Hydrotheca adnate for over half length, then curved outwards, 0,14—

0,3 mm in abcauline height and 0,11-0,15 mm in marginal diameter. Margin

untoothed, thickened on abcauline edge. No internal teeth.

Gonothecae borne on front of stem below hydrothecal pairs, barrel-

shaped, with shallow transverse annulations and broad distal aperture con-

taining a ring of internal spiny processes, male and female on separate stems.

Male reaching 1,2 mm in length and 0,8 mm in maximum diameter. Female

reaching 1,5 mm in length and 1,1 mm in maximum diameter, with external

marsupium.

Variation. Although the type material of this species was said to branch ‘sparely

and irregularly’, the South African material only rarely produces a single short

lateral branch. The spacing of the hydrothecal pairs is always regular, though

occasionally one of the obliqué nodes may be missing.

Distribution outside South Africa. California (type locality) and neighbouring

areas of the eastern Pacific, Walter’s Shoal in southern Indian Ocean.

Distribution in South Africa. Transkei coast, littoral, on coralline algae. 31/29

(I), 31/30 (1)

Salacia disjuncta Millard, 1964

Fig. 90D—-F

Salacia disjuncta Millard, 1964: 31, fig 10A-F.

Diagnosis. Stem moderately stiff, unfascicled, bearing opposite hydrocladia,

reaching a maximum height of 36 mm, divided by straight nodes into fairly

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 275

Fig. 90.

Salacia desmoides. A, stem with male gonophores; B, stem with female gonophore;

C, hydrothecae with hydranths and opercula.

Salacia disjuncta. D, stem; E, part of stem with origins of hydrocladia; F, hydrothecae.

Scale: D in mm, the rest in mm/10.

276 ANNALS OF THE SOUTH AFRICAN MUSEUM

regular internodes, each of which bears three pairs of opposite or subopposite

hydrothecae and one pair of hydrocladia arising between the first and second

pairs of hydrothecae. Hydrocladia forming a right angle with stem, the two

rows in one plane. The two rows of hydrothecae seated on the sides of the stem

and well separated from one another.

Hydrocladium much narrower than stem, with very distinct, constricted

nodes at irregular intervals, each internode with a long slender proximal part

without hydrothecae and a wider distal part bearing a closely compressed group

of 2-3 pairs of opposite or subopposite hydrothecae. The two rows of hydro-

thecae seated on the sides of the hydrocladia and not contiguous with one

another in the centre.

Hydrotheca tubular, curved outwards, adnate for 3-# length, narrowing

slightly to margin, 0,3-0,4 mm in abcauline height and 0,10-0,14 mm in marginal

diameter. Margin untoothed, transversely widened, thickened on abcauline

edge. No internal teeth.

Gonothecae unknown.

Variation. Stem internodes occasionally bear only one pair of hydrothecae;

those at the base of the stem are irregular in length and bear no hydrocladia.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 32°15,2’S/

25° 5). 1-5 0)am

Distribution in South Africa. False Bay and Agulhas Bank, 29-84 m. 34/18 (s),

32/28 (s), 33/28 (s)

Genus Sertularella Gray, 1847

Syn. Thecocladium Allman, 1886.

Diagnosis. Stem erect, branched or unbranched. Stem and hydrocladia bearing

alternate hydrothecae which form two longitudinal rows. Hydrotheca sessile,

with four marginal teeth and an operculum of four triangular valves seated in

the bays between the teeth and meeting in the centre as a pyramid. Hydranth

with abcauline caecum.

Type species: Sertularia polyzonias Linnaeus, 1758.

KEY TO SPECIES

(Doubtful species not included: for these see p. 305; for types of hydrothecal shape see p. 241)

1. More than one hydrotheca to an internode : 2

— Only one hydrotheca to an internode (though nodes may be tadieenet | in older stems) 3

2. Cauline hydrothecae regularly spaced, three to an internode. Hydrocladial hydro-

thecae grouped, with a variable number to an internode. Hydrocladia arising below

cauline hydrothecae : ue S. diaphana

— Stem and hydrocladia similar, with srouped hydrothecae, a variable number to an

internode. Hydrocladia arising from within cauline hydrothecae Be S. flabellum

3. Internal teeth present within hydrothecal margin Me My ae 44 eC!

No internal teeth .. re ude ee = be ys ee a eS.

Wi.

ES:

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA PAS

. Three internal teeth, one of them median adcauline or abcauline suacgial two

small additional ones too) . 5

Four internal teeth, which always a alternate with ‘marginal teeth (one or more occa-

sionally missing) .. nes oa a ie AAs a Ii |

Hydrotheca very large (over 0,7 mm in aniline height) ay 6

Hydrotheca small to medium (under 0,8 mm in abcauline height). ‘Internal teeth

always one abcauline, two latero-adcauline |... ay Vii

Hydrotheca adnate for over half height. Internal teeth one Meouline. two ators.

abcauline De: : S. goliathus

Hydrotheca adnate for under half height, ‘Internal teeth one abcauline, two latero-

adcauline.. ve S. leiocarpa

Mature stem fascicled tad re arenes Beeched: Benning typically pinnate

and in one plane... 8

Mature stem unfascicled, short, mnbranched or a nee with ih —5 irregular pranches 10

Hydrotheca not annulated, axis distinctly bent outwards and margin tilted away

from stem .. : Bs an op S. arbuscula

Hydrotheca with distinct transverse annulations Be a es,

Hydrotheca small (under 0,5 mm in abcauline height), Searcy narrowing to mouth

(which is under 0,2 mm in eoeees margin Pe alg: to axis or tilted away

from stem .. : S. gilchristi

Hydrotheca of medium size (0, 5-0, 7 mm in ‘abcauline height), not markedly

narrowing to mouth (which is over 0,2 mm in ie margin perpendicular to

axis or tilted towards stem : ae S. agulhensis

Hydrotheca annulated on nd caulinie seul Abeauline, margin not produced and

margin tilted away from stem ae S. natalensis

Hydrotheca not annulated. Abcauline margin generally produced and margin

either tilted towards stem or perpendicular to axis et re .. iS. mediterranea

. Mature stem fascicled, branching pinnately and in one plane. Hydrotheca distinctly

annulated on adcauline surface .. .. S. pulchra

Mature stem unfascicled, unbranched or ‘branching iegulacly Hydrotheca not, or

only faintly, annulated w an 3 ele

. Stem short, unbranched, or at most with one or two sbreuiches: Hy araiiess with

margin perpendicular to axis and with convex or straight abcauline wall _S. fusiformis

Stem long, flexuous and straggling, with irregular branches. Hydrotheca with margin

tilted away from stem and with concave abcauline wall he 5 S. polyzonias

. Hydrotheca with distinct ridged annulations continued all the way round wall ee

Hydrothecal wall smooth, or with weak annulations on adcauline surface only .. 16

. Hydrotheca usually with six or seven annulations spread evenly over entire length,

never less than four; abcauline marginal tooth produced and longer than others S. striata

Hydrotheca with not more than three annulations restricted to free part; Sai oe

teeth of equal size .. ie He ae see ls)

. Stem long and tangled, branching Henley. aoe oar to stem for half

or more of height .. : S. capensis

Stem short and unbranched, beme at moet eieht hydrothecae and ‘often only one.

Hydrotheca adnate to stem for less than half height .. i: S. annulaventricosa

. Hydrocladial hydrothecae overlapping, the tip of one reaching about half-way up the

next. Free part of adcauline wall of oper almost touching internode, with an

open angle of less than 20° : S. congregata

Hydrothecae not overlapping, the tip of one seldom reaching Above base of next. Free

part of adcauline wall of eee at well away from internode, with an

open angle of over 40° ss : ie - ae wld,

Stem flexuous and straggling aie to aes eat, out of fluid) Se S. polyzonias

Stem stiff (able to support itself out of fluid) .. ae an ore a re tS

Stem strongly fascicled and branching in one plane; final branches pinnate, giving off

regularly alternate hydrocladia .. at ahi ae wi ti 2) wadubia

278 ANNALS OF THE SOUTH AFRICAN MUSEUM

— Stem unfascicled or (rarely) lightly fascicled; unbranched or with one order of

branches only oe Ae = ans - er an a ae S20 19

19. Hydrotheca small to medium (under 0,7 mm in abcauline height), abcauline edge

produced and margin tilted towards adcauline side, adcauline free part weakly

annulated .. S. africana

— Hydrotheca large (over 0, Tn mm in Bpeauline height), abcauline edge not produced and

margin perpendicular to axis or tilted towards abcauline side, adcauline free part

smooth es _ oS ae au 2 ie et ee a va 220

20. Hydrotheca with a marked angle in adcauline wall; adcauline free part straight or

concave. Gonotheca annulated .. .. S. megista

— Hydrotheca with adcauline wall curved ‘smoothly outwards, adcauline free part

convex. Gonotheca smooth 50 i oe Be BS ae S. leiocarpa

Sertularella africana Stechow, 1919

Fig. 91A—C

Sertularella fusiformis: Warren, 1908: 295, fig. SC—D.

Sertularella africana Stechow, 1919b: 83. Stechow 1923c: 179, fig. V. Millard, 1957: 207,

figs 101, 11F.

Diagnosis. Stem stiff, short, unfascicled, unbranched or at most with a few

short branches, reaching 18 mm in height; divided into internodes by oblique

nodes sloping in alternate directions, each internode bearing one hydrotheca;

usually with an annulation above each node.

Hydrotheca small, adnate for about half adcauline length, with weak

transverse annulations on free part of adcauline wall, with abcauline margin

and tooth produced so that margin is tilted towards adcauline side, abcauline

wall more or less straight, adcauline wall convex, 0,4-0,6 mm in abcauline

height and 0,18-0,3 mm in diameter. No internal teeth.

Gonothecae borne on front of stem immediately below the hydrothecae,

ovate, annulated, male with three distinct marginal spines and narrow aperture,

female with less distinct spines, wider aperture and external marsupium.

Variation. Although most hydrothecae conform to the characteristic shape,

those near the base of the stem are often nearly symmetrical in side view, with

the margin perpendicular to the axis, thus approaching the shape of S. fusiformis.

Sometimes a few hydrothecae of a colony have the abcauline wall of the hydro-

theca slightly bent out, which also causes the margin to be perpendicular to the

axis. The adcauline annulations are variable and may extend all round the wall,

or be absent altogether in certain (generally older) hydrothecae.

The gonothecae vary in the extent and number of the annulations, and may

rarely have only two, or as many as four, marginal spines.

Distribution. Endemic to South Africa. Type locality: Park Rynie, Natal.

Distribution in South Africa. Lambert’s Bay to Natal, littoral to 27 m. One of the

few hydroids which is fairly common in the littoral region. 32/18 (s), 33/17 (J),

33/18 (I), 34/18 (1, s), 34/21 (1), 33/25 (1, s, on turtle), 33/27 (1), 32/28 (1), 30/30

(I)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 279

Sertularella agulhensis Millard, 1964

Fig. 91D-E

Sertularella agulhensis Millard, 1964: 35, fig. 12A.

Diagnosis. Stem stiff, fascicled, branched or unbranched, giving off alternate or

subalternate hydrocladia in one plane, reaching 82 mm in height. Hydrocladia

arising from immediately below hydrothecae. Stem and hydrocladia divided

into internodes by oblique nodes sloping in alternate directions, but nodes often

indistinct in older parts; each internode bearing one hydrotheca.

Hydrotheca of medium size, adnate for about half adcauline length,

annulated, with about six transverse annulations continued all round wall,

abcauline wall more or less straight, with margin more or less perpendicular to

axis and not particularly narrowed, 0,5-0,7 mm in abcauline height and 0,2-

0,3 mm in marginal diameter. Three small internal teeth, one abcauline and two

latero-adcauline.

Gonotheca unknown.

Variation. The hydrocladia are usually alternate, arising below every third

hydrotheca, but sometimes subalternate, arising below every first and third

hydrotheca. Other variations may also occur.

The abcauline side of the thecal margin is sometimes more produced than

the rest, with the result that the margin may be tilted slightly towards the

adcauline side. There may or may not be a slight concavity in the abcauline wall.

The internal teeth are constant in number and position, but may vary in size,

e.g. the latero-adcauline teeth may be smaller than the abcauline and vice

versa.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 34°51’S/

SESS 13, 2A iam,

Distribution in South Africa. False Bay and Agulhas Bank south of Cape

Agulhas, 22-42 m, rare. 34/18 (s), 34/19 (s)

Sertularella annulaventricosa Mulder & Trebilcock, 1915

Fig. 91 F-H

Sertularella tenella: Hartlaub, 1901a: 64 (pp., material from Algoa Bay), pl. 5 (fig. 24).

Sertularella annulaventricosa Mulder & Trebilcock, 1915: 54, pl. 7 (fig. 1), pl. 8 (figs 44a).

Watson, 1973: 172, fig. 23.

Sertularella undulata Bale, 1915: 285, pl. 46 (fig. 1).

Sertularella capensis delicata Millard, 1964: 38, fig. 12B—D.

Diagnosis. Stem unfascicled, unbranched, short and slender, geniculate, reaching

5 mm in maximum height; divided into internodes by oblique nodes sloping in

alternate directions, each internode bearing one hydrotheca; with not more

than eight hydrothecae and often only one; generally annulated at base and in

region of nodes.

Hydrotheca small, adnate for under ha:f adcauline height, with one, or

280 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 91.

Sertularella africana. A, hydrothecae; B, stem; C, male gonotheca.

Sertularella agulhensis. D, hydrothecae; E, stem.

Sertularella annulaventricosa; F, solitary hydrotheca and upright stem; G and H, solitary

hydrothecae.

Sertularella arbuscula. J, stem; K, hydrothecae; L, gonotheca.

Scale: B, E and J in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 281

occasionally two, sharply ridged annulations continued all the way round free

part, barrel-shaped with margin perpendicular to axis, 0,3—-0,5 mm in abcauline

height and 0,3 mm in marginal diameter. No internal teeth. Mouth wide, its

diameter only slightly less than the widest part of the hydrotheca, round in

section.

Gonotheca unknown.

Variation and remarks. The stem is always delicate, but varies in the length

of internode and amount of annulation. Stems with only one hydrotheca are

common; these can be distinguished from the genus Calamphora by the extension

of the growing point of the internode behind the hydrotheca.

This material was originally described as a subspecies of S. capensis, to

which the hydrotheca shows a similarity. However, the growth-form is different

and Mrs J. Watson was kind enough to draw my attention to the resemblance to

S. annulaventricosa, with which it has now been synonymized.

Distribution outside South Africa. South Australia and Tasmania. Type locality:

Queenscliff, Australia.

Distribution in South Africa. Port Elizabeth to Durban in 47-53 m. 33/25,

32/28 (s), 31/29 (s), 29/31 (s)

Sertularella arbuscula (Lamouroux, 1816)

Fig. 91J—L

Sertularia arbuscula Lamouroux, 1816: 191, pl. 5 (fig. 4).

Sertularella crassipes Allman, 1886: 133, pl. 8 (figs 4-5).

Sertularella arbuscula: Millard, 1957: 208, figs 10B, 11C. Millard, 1964: 37.

Diagnosis. Stem stiff, fascicled, branching irregularly near base but pinnately

and in one plane near extremities, reaching 300 mm in height. Hydrocladia

arising from immediately below hydrothecae, the two rows in one plane. Stem

and hydrocladia divided into short internodes by oblique nodes sloping in

alternate directions, each internode bearing one hydrotheca.

Hydrotheca small to medium, adnate for about half adcauline length,

smooth, with axis distinctly bent outwards and margin tilted towards abcauline

side, 0,4-0,6 mm in abcauline height and 0,15—0,3 mm in marginal diameter.

Three internal teeth, one abcauline and two latero-adcauline.

Gonothecae borne on stem and hydrocladia immediately below the hydro-

thecae, spindle-shaped, quite smooth or (occasionally) annulated in distal half;

margin with a variable number of short spines.

Variation. Once known this common species is easily recognized in spite of

much variability. Occasionally the ‘outward bend’ in the hydrotheca is not so

marked as usual and occasionally the abcauline side of the margin is slightly

produced. Neither variation is sufficiently marked to prevent the perpendicular

passing through the adcauline wall, and both are usually limited to a few hydro-

thecae of a colony. The width of the thecal mouth is variable and a form with

Doo ANNALS OF THE SOUTH AFRICAN MUSEUM

an extra narrow mouth often occurs, a variation usually common to all hydro-

thecae of a colony. The internode length and amount of adcauline thecal wall

which is adnate to the internode are likewise variable. The internal thecal teeth

are constant in position, though occasionally they may be missing in a few hydro-

thecae of a colony with thin perisarc or in very old hydrothecae. Two small acces-

sory internal teeth, one on each side of the abcauline one, commonly occur,

and the abcauline wall may be thickened below the level of the abcauline tooth.

The smooth gonotheca is most characteristic, but occasional examples

occur with corrugated or annulated walls, both in the male and in the female.

The width of the mouth and the number of marginal spines are variable. Some

gonothecae bear an external marsupium.

Distribution outside South Africa. Australasia, southern and western Indian

Ocean, Vema Seamount. Type locality: Australasia.

Distribution in South Africa. Very common round most of the coast from

Saldanha Bay to Mocambique, littoral to 219 m. 33/17 (s), 33/18 C, s), 34/18

(s), 34/20 (s), 35/20 (),. 34/21 (s), 35/21 (d), 34/22 (s), 35/22 @s 34/23nGae):

34/24 (d), 33/25 (s), 34/25 (s), 33/26 (s), 34/26 (d), 33/27 (s), 33/28 (s), 32/28

(s), 32/29. (d), 31/29 (s),-31/30 (Ss), 30/30 G), 30/31 G, d), 29/31 G aR297321G):

28/32 (s, d), 26/32 (s), 24/35 (s, d)

Sertularella capensis Millard, 1957

Fig. 92H-K

Sertularella capensis Millard, 1957: 210, fig. 10H.

Sertularella capensis capensis: Millard, 1964: 38, fig. 12F.

Diagnosis. Hydrorhiza profuse and tangled, not firmly attached to substratum.

Stem unfascicled, flexuous and straggling, branching irregularly, with a tendency

towards stolonization resulting in a tangled mass reaching 40 mm in height;

divided into internodes by oblique nodes sloping in opposite directions, each

internode bearing one hydrotheca. Branches arising from below hydrothecue,

similar to stem.

Hydrotheca small, adnate for half adcauline height or a little more, with

1-3 (usually 2) sharply ridged annulations continued all the way round free part,

fusiform, with margin generally perpendicular to axis, but sometimes tilted

slightly towards abcauline side, 0,4-0,5 mm in abcauline height and 0,2-0,3

mm in marginal diameter. No internal teeth. Mouth wide, its diameter only

slightly less than the widest part of the hydrotheca.

Gonothecae borne on front of stem immediately ‘below nydrothecae,

elongate-oval, annulated throughout, with up to 16 narrow, ridged annulations.

Margin with four or more spines. No external marsupium.

Variation and remarks. The appearance of the stem is variable and subject to

abnormalities resulting from stolonization. It may be straight or geniculate,

and there may be a suggestion of an annulation immediately above and below

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 283

each node. The gonotheca may have as many as seven marginal spines.

The hydrotheca is similar to that of Sertularia annulata Allman, 1888

(=Sertularella gayi var. annulata), but the growth-form is different, the latter

species haying a stiff and fascicled stem. It also shows resemblances to

S. tenella (Alder, 1856), but differs in the wider mouth, smaller number of annu-

lations and larger proportion of wall adnate. It might possibly be included as

a variety*of S. polyzonias, but lacks the concave abcauline wall of the latter.

Distribution. Endemic to South Africa. Type locality: False Bay, 27-28 m.

Distribution in South Africa. False Bay, and Agulhas Bank in the East London

area, 27-58 m. 34/18 (s), 33/27, 33/28 (s), 32/28 (s)

Sertularella congregata Millard, 1964

Fig. 92D-G

Sertularella congregata Millard, 1964: 39, fig. 13A—D.

Diagnosis. Stem stiff, fascicled, branched or unbranched, giving off alternate

hydrocladia in one plane, reaching 70 mm in height. Hydrocladia arising from

immediately below every third hydrotheca of stem, alternately on right and left.

Stem and hydrocladia typically divided into short internodes by oblique nodes

sloping in alternate directions, each internode bearing one hydrotheca, but

hydrothecae crowded and overlapping in distal parts of hydrocladia where

also nodes are not visible.

Hydrotheca small, adnate for half or more adcauline length, smooth,

axis straight in basal half and curved outwards in distal half, margin tilted

towards abcauline side, walls practically parallel, 0,4-0,5 mm in abcauline

height and 0,19-0,2 mm in marginal diameter. No internal teeth. A perisarcal

thickening present on abcauline wall and continued half-way round wall as a

ridge below margin.

Gonotheca borne on anterior surface of hydrocladium next to the base of

a hydrotheca, spindle-shaped, with about eight low annulations in distal region;

margin with five short spines.

Variation. The stem may be simple and pinnate, or spreading and fan-shaped

in which case one or more hydrocladia are replaced by long, fascicled and pin-

nate branches.

The interval between successive hydrothecae is variable. The latter are

moderately well spaced on the stem, with the margin of one just overreaching

the base of the next on the opposite side, but very close-set towards the distal

parts of the hydrocladia, with the margin of one sometimes reaching the base

of the next on the same side. Nodes may be completely invisible (in fascicled

parts of stem and crowded regions of hydrocladia) or quite distinct. The shape

and structure of the hydrotheca is very constant in the specimens known, though

it'is possible that the thickening on the abcauline thecal wall may, as in many

other species, be a variable feature.

284 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 92.

Sertularella flabellum. A, hydrothecae; B, gonotheca; C, colony.

Sertularella congregata. D, part of stem and hydrocladium; E, gonotheca; F, stem;

G, hydrothecae.

Sertularella capensis. H, hydrothecae; J, gonotheca; K, colony.

Scale: C, F and K in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 285

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 33°7,3’S/

28°1'E, 88 m.

Distribution in South Africa. Two records only from the same area on the

Agulhas Bank, 86-88 m. 33/28 (s)

Sertularella diaphana (Allman, 1886)

Fig. 93A—D

Thuiaria diaphana Allman, 1886: 145, pl. 18 (figs 1-3).

Sertularella diaphana: Billard, 1925a: 157, fig. 22, pl. 7 (figs 12-13). Millard, 1958: 188, fig.

7C-D.

Diagnosis. Stem thick and fascicled, branching profusely and irregularly,

reaching 150 mm in height. Final branches pinnate, giving rise to alternate

hydrocladia which are more or less in one plane. Stem and branches divided

into internodes by oblique nodes sloping alternately to left and right; each

internode bearing three hydrothecae and one hydrocladium, the latter arising

just below the third hydrotheca. Hydrocladium with distant oblique nodes and a

variable number of hydrothecae to an internode. The two rows of hydrothecae

on stem, branches and hydrocladia not in one plane but shifted onto the anterior

surface.

Hydrotheca completely adnate or very nearly so, smooth, curved out-

wards, with margin tilted towards abcauline side, 0,4-0,6 mm in adcauline height

and 0,2 mm in marginal diameter. Marginal teeth low. No internal teeth.

Gonothecae borne on the anterior surface of the hydrocladia, elongated,

tapering proximally, truncated distally, with faint longitudinal striations. No

external marsupium. No marginal spines.

Variation. Billard (1925a) distinguished several varieties of this species from the

Dutch East Indies, but all South African material belongs to the normal variety.

The perisarc is thin in the younger parts of the colony but heavier in older

parts, where the abcauline thecal wall is thickened just below the margin.

Distribution outside South Africa. Circumglobal in tropical and subtropical

waters. Type locality: Moreton Bay, Queensland, Australia.

Distribution in South Africa. Coasts of Natal and Mocambique from Durban

northwards, 12-64 m. 30/30 (s), 29/31 (s), 26/32 (s), 25/33 (s)

Sertularella dubia Billard, 1907

Sertularella dubia Billard, 1907a: 344, fig. 3, pl. 25 (fig. 1).

Diagnosis. Stem stiff, fascicled, branched, giving off alternate hydrocladia in

one plane. Hydrocladia arising from immediately below every third hydrotheca,

alternately on right and left. Stem and hydrocladia divided into internodes by

poorly marked oblique nodes sloping in alternate directions, each internode

bearing one hydrotheca.

286 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 93.

Sertularella diaphana. A, stem; B, gonotheca; C, part of stem with origins of hydrocladia;

D, hydrothecae.

Sertularella fusiformis. E, fertile colony; F, male gonotheca; G, hydrothecae (form with

crowded hydrothecae).

Scale: A and E in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 287

Hydrotheca small to medium, adnate for about half adcauline height,

usually smooth, adcauline wall curved or bent outwards, abcauline wall straight

or slightly concave; margin usually tilted towards abcauline side, narrowed.

No internal teeth. A perisarcal thickening present on abcauline wall at about

two thirds height.

Distribution. Macalonga, Mocambique, 22 m (type locality).

Only the following subspecies present in South Africa.

Sertularella dubia magna Millard, 1958

Fig. 94A—F

Sertularella dubia var. magna Millard, 1958: 189, fig. 7A.

Sertularella dubia magna: Millard, 1964: 41, fig. 14A—F.

Diagnosis. Similar to nominal subspecies but of larger dimensions, hydrotheca

over 0,45 mm in abcauline height (0,5-0,7 mm) and over 0,20 mm in marginal

diameter (0,2—0,3 mm). Stem reaching 135 mm in height.

Gonotheca (not known in the nominal subspecies) borne on hydrocladium

immediately below hydrotheca, spindle-shaped, annulated in distal region;

margin with a variable number of short spines.

Variation. The internode length varies, so that the hydrothecae may be well

spaced or set fairly close together. Nodes are visible only in the young parts of

the colony.

The hydrothecae are very variable in shape and appearance. They may

have light corrugations on the free part of the adcauline wall and thus resemble

those of S. gayi, or the abcauline marginal tooth may be elongated, with the

result that the margin may be tilted towards the adcauline side. All intermediate

forms may occur. More heavily chitinized hydrothecae have a very distinct

abcauline perisarcal thickening, but this is scarcely noticeable in lightly built

colonies and young hydrothecae.

Remarks. The general appearance and growth-form are similar to those of

S. arbuscula and S. gayi. From the former it is distinguished by the absence of

internal teeth, and from the latter by the nature of the gonotheca (bilabiate in

S. gayi).

Some specimens show resemblances to S. crassicaulis, but can be disting-

uished from it by the method of growth (dichotomous in S. crassicaulis).

Distribution. Endemic to South Africa. Type locality: off Cone Point, Natal,

62 m.

Distribution in South Africa. False Bay to northern Natal on the east, 27-232 m.

34/18 (s), 34/21 (s), 33/25 (s), 34/25 (d), 33/27 (s), 33/28 (s), 32/28 (s), 30/30 (s),

50) Si (S) e292) SiGe) 29) S28). 28/32 (Ss, a)

288 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 94.

Sertularella dubia magna. A-D, hydrothecae; E, gonotheca; F, stem.

Sertularella gilchristi. G, stem; H, gonotheca; J, hydrothecae.

Scale: F and G in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 289

Sertularella flabellum (Allman, 1886)

Fig. 92A—C

Thecocladium flabellum Allman, 1886: 149, pl. 19 (figs 4-5). Allman, 1888: 81, pl. 38.

Sertularella flabellum: Billard, 1910: 12, fig. 4. Millard, 1957: 212, figs 10G, 11G.

Diagnosis. Hydrorhiza attached at intervals only. Stem unfascicled, unbranched

or branching irregularly, with branches always arising from within hydrothecae,

reaching 99 mm in height. Stem and branches similar, in one plane, with distant

nodes and a variable number of hydrothecae to each internode. The two rows

of hydrothecae in one plane.

Hydrotheca adnate for two-thirds of adcauline height or more, smooth,

curved outwards, with margin tilted towards abcauline side, 0,4-0,5 mm in

abcauline height and 0,2-0,4 mm in marginal diameter. Marginal teeth low.

No internal teeth.

Gonothecae borne on stem immediately below hydrothecae, pear-shaped,

strongly annulated. No external marsupium. No marginal spines.

Variation. This species is easily recognized by its characteristic growth-form.

Both stems and branches have a strong tendency towards stolon formation.

The hydrothecae may be closely set, so that the margin of one almost overlaps

the base of the next on the same side, or may be much more distant, when

two hydrothecae on the same side are separated by a distance equal to their own

length.

The hydrotheca normally has a thin perisarc, but may be thickened at

the margin and at the point where the abcauline caecum attaches. There is a

marked tendency towards regenerated margins.

The gonotheca is annulated to a varying degree. The annulations normally

extend from the distal end downwards for about two-thirds of the length, but

may reach almost to the base.

Distribution. Endemic to South Africa and the Vema Seamount. Type locality

unknown.

Distribution in South Africa. Common from Saldanha Bay on the west round

the south coast to Richard’s Bay on the east, 10-232 m. 33/17 (s), 33/18 (s),

34/18 (s), 34/19 (s), 34/20 (s), 34/21 (s), 35/21 (d), 34/22 (s), 35/22 (d), 34/23

(d), 33/25 (s), 34/25 (s, d), 33/26 (s, d), 33/27 (s), 32/28 (s), 30/30 (s), 30/31 (s),

29/31 (d)

Sertularella fusiformis (Hincks, 1861)

Fig. 93E-G

Sertularia fusiformis Hincks, 1861: 253, pl. 6 (figs 7-8).

Sertularella lineata: Stechow, 1925a: 469, fig. 29.

Sertularella fusiformis forma glabra Broch, 1933: 69, fig. 27.

Sertularella fusiformis: Millard, 1957: 213, fig. 10C—E.

Diagnosis. Stem short and stiff, unfascicled, unbranched or with at most one or

two short branches, reaching 22 mm in height. Branches, when present, arising

290 ANNALS OF THE SOUTH AFRICAN MUSEUM

from below hydrothecae. Stem and branches divided into internodes by oblique

nodes sloping in alternate directions, each internode bearing one hydrotheca.

Hydrotheca small to medium, adnate for 3-} adcauline length, smooth

or faintly annulated, generally symmetrical and flask-shaped in side view, with

margin perpendicular to axis, 0,4-0,6 mm in abcauline height and 0,17-0,3 mm

in marginal diameter. Four small and delicate internal teeth of which one or

more may be missing, alternating with marginal teeth.

Gonotheca borne on front of stem immediately below hydrotheca, spindle-

shaped, annulated at least in distal half; margin narrow, with three or four

spines.

Variation. This small species is common as an epizooite on other hydroids.

The stem may be geniculate or quite straight, and often has one or more distinct

annulations at the base of each internode. The two rows of hydrothecae may be

in one plane, or displaced onto one surface of the stem. The hydrothecae may be

well separated or overlapping.

In the hydrotheca the most common variations are an elongation of the

abcauline margin and tooth, and a bending out of the abcauline wall. Since

both variations usually occur together, the line drawn perpendicular to the

margin may be displaced so that it passes through the adcauline wall or, rarely

in the other direction, so that it passes through the hydropore. The abcauline

wall may be convex, straight, or slightly concave. The wall is normally quite

smooth, but occasionally shows faint indications of transverse annulations, but

never as pronounced as in f. ornata Broch. The internal teeth are constant in

size and position, but the full complement of four is not always present. There

may be a low thickening on the abcauline wall below the level of the internal

teeth.

Remarks. This is one of the more difficult ‘intergrading’ species and shows

variations in thecal shape approaching the polyzonias type (with concave abcau-

line wall), and the africana type (with straight, elongated abcauline wall). The

form with overlapping hydrothecae is reminiscent of S. congregata. The cri-

terion for identification is taken to be the presence of small internal teeth, which

always alternate with the marginal teeth. Thus, even though some teeth are

missing, the species can be distinguished from the three-toothed ones by the

position.

Distribution outside South Africa. North Atlantic and Mediterranean, with one

record from the west coast of North America. Type locality: South Devon, U.K.

Distribution in South Africa. Lambert’s Bay to East London, littoral to 70 m.

32/18 (1), 33/17 (1), 33/18 (1, s), 34/18 (1, s), 34/22 (s), 33/27, 32/28 (s)

Sertularella gilchristi Millard, 1964

Fig. 94G_-J

Sertularella gilchristi Millard, 1964: 44, figs. 12E, G-H.

Diagnosis. Stem stiff, fascicled, branching and rebranching profusely in an

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 291

irregular pinnate fashion and usually in one plane, reaching 69 mm in height.

Final branches (hydrocladia) arising from immediately below hydrothecae

with irregular spacing. Stem and hydrocladia divided into internodes by oblique

nodes sloping in alternate directions, but nodes indistinct in older parts; each

internode bearing one hydrotheca.

Hydrotheca small, adnate for just under half adcauline length, annulated,

with three or more transverse annulations usually continued all round wall,

fusiform and usually slightly curved outwards, markedly narrowing to margin,

with margin tilted towards abcauline side, 0,3—-0,4 mm in abcauline height and

0,11-0,14 mm in marginal diameter. Three internal teeth, one large abcauline

and two smaller latero-adcauline.

Gonothecae borne on hydrocladia immediately below hydrothecae,

spindle-shaped, annulated, with very narrow opening and three or (rarely)

four sharp marginal spines.

Variation. The general effect of the colony is bushy, for branching is not always

strictly in one plane. The two rows of hydrothecae are usually in One plane, but

may be slightly offset to one surface. A spiral annulation may or may not be

present above each node. The internode length is variable.

The amount of annulation on the hydrotheca is variable, and may be

indistinct or confined to the adcauline side. The hydrotheca is sometimes

quite symmetrical, but is more typically bent outwards and the margin tilted

towards the abcauline side. Rare hydrothecae may occur in which the mouth is

less narrow. The internal teeth are constant in position, and always well

developed, and in many hydrothecae two minute extra ones occur, one on each

side of the median abcauline one.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 33°3’S/

Die) ie D1, 11.

Distribution in South Africa. Agulhas Bank, in the Port Elizabeth—East London

area, 27-90 m. Rare. 34/25 (s), 33/27 (s)

Sertularella goliathus Stechow, 1923

Fig. 9SA—C

Sertularella goliathus Stechow, 19236: 112. Stechow, 1925a: 481, fig. 37. Millard, 1957: 215,

figs 10A, 11A.

Diagnosis. Stem stiff and fascicled, giving off hydrocladia in an irregularly

pinnate fashion, reaching 79 mm in height. Hydrocladia arising from

immediately below hydrothecae, the two rows in one plane. Stem and hydro-

cladia divided into short internodes by oblique nodes sloping in alternate direc-

tions, but nodes indistinct in older parts; each internode bearing one hydro-

theca.

Hydrotheca large, adnate for about two-thirds adcauline length, smooth,

adcauline wall bent sharply outwards at top of adnate part, margin perpendicular

292 ANNALS OF THE SOUTH AFRICAN MUSEUM

to axis, abcauline and free part of adcauline wall slightly concave, margin

narrow; 0,9-1,1 mm in abcauline height and 0,3-0,4 mm in marginal diameter.

Three large internal teeth, one adcauline and two latero-abcauline.

Gonothecae borne on hydrocladial internodes on the same level as, and

on the opposite side to, the base of the hydrotheca, spindle-shaped, with about

five rounded annulations; margin with three spines.

Variation. Although the mature colony is fascicled, young stems are unfascicled

and often without hydrocladia.

Although the thecal margin is normally perpendicular to the axis, slight

deviations to either side may occur, so that the perpendicular may pass through

the lower part of the adcauline wall or through the hydropore. Usually the

free part of the adcauline wall is at right angles to the internode, but the angle

may be smaller than this, particularly at the distal ends of hydrocladia. Internal

teeth are always present, and constant in number and position.

The gonotheca may have as few as three annulations restricted to the distal

end, but this is rare.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank.

Distribution in South Africa. West coast of Cape Peninsula to Mossel Bay in

8-155 m. 34/18 (s), 34/20 (s), 35/20 (d), 34/21 (s), 35/22 (d)

Sertularella leiocarpa (Allman, 1888)

Fig. 95D-F

Sertularia leiocarpa Allman, 1888: 52, pl. 25 (fig. 1—-1a).

Sertularella leiocarpa: Stechow, 1925a: 477, fig. 35. Vervoort, 19665: 128, figs 31-32. Millard,

1968: 269, fig. 4A-C.

Diagnosis. Stem moderately stiff (just able to support itself out of fluid), unfas-

cicled or lightly fascicled at base, giving off roughly alternate hydrocladia in

one plane, reaching 42 mm in height. Hydrocladia arising from immediately

below hydrothecae. Stem and hydrocladia divided into fairly long and slender

internodes by oblique nodes sloping in alternate directions, but nodes indistinct

in older parts; each internode bearing one hydrotheca.

Hydrotheca tubular, adnate for 4-4 adcauline length, smooth, curving

gently outwards, with straight or concave abcauline wall and smoothly convex

adcauline wall, narrowing markedly to mouth, margin tilted towards abcau-

line side, 0,7—1,2 mm in abcauline height and 0,2-0,4 mm in marginal diameter.

Usually without internal teeth.

Gonothecae borne on stem on the same level as, and on the opposite side

to, the base of the hydrotheca, spindle-shaped, completely smooth; margin

with three or four short spines.

Variation. A few hydrothecae show very faint traces of annulation on the free

part of the adcauline wall. Although normally there are no internal teeth, one

of the larger colonies has minute internal teeth in some hydrothecae only, either

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 293

van

Fig. 95.

Sertularella goliathus. A, gonotheca; B, hydrothecae; C, stem (somewhat damaged).

Sertularella leiocarpa. D, hydrotheca; E, part of colony; F, part of stem with hydrothecae

and gonotheca.

Scale: C and E in cm, A and F in mn, the rest in mm/10.

294 ANNALS OF THE SOUTH AFRICAN MUSEUM

two latero-adcauline, or two latero-adcauline plus one abcauline. Vervoort

reports traces of four internal teeth in some hydrothecae of his material. This is

a species in which the presence or absence of internal teeth is variable.

Distribution outside South Africa. South Atlantic and southern Indian Ocean.

Type locality: Nightingale Island, 183-274 m.

Distribution in South Africa. A deep-water species. Scattered records from the

west coast of the Cape Peninsula, Agulhas Bank, Natal and Mocambique,

200-595 m. 34/18 (); 35/22 (d, vd), 29/31 @), 25/35 (vd)

Sertularella mediterranea Hartlaub, 1901

Sertularella mediterranea Hartlaub, 190la: 86, pl. 5 (figs. 10-11, 15-16). Billard, 1922: 107,

figs 3-4. Stechow, 1923c: 189, 192, figs C1, Dta. Millard, 1957: 215, figs 10E, 11B.

Sertularella ellisi f. mediterranea: Patriti, 1970: 38, fig. 49.

Diagnosis. Stem stiff, unfascicled, unbranched or with a few irregular branches,

divided into internodes by oblique nodes sloping in alternate directions, each

internode bearing one hydrotheca. Branches similar to stem.

Hydrotheca smooth, narrowing to mouth; with more or less straight abcau-

line wall and double curvature in adcauline wall, first convex, then concave;

with abcauline margin and tooth typically produced and margin thus tilted

towards stem. Three strong internal teeth, one abcauline and two latero-

adcauline.

Gonothecae borne on the stem opposite the bases of the hydrothecae,

spindle-shaped, annulated in distal half to a varying degree, with three or four

marginal spines and distinctly narrowed just below them.

KEY TO SUBSPECIES

1. Hydrotheca bilaterally symmetrical, with lateral teeth equally developed; adnate for

not less than 3 adcauline length .. S. m. mediterranea

— Most of the hydrothecae with right and ‘left margins not symmetrical, one lateral

tooth being larger than the other. Hydrotheca adnate for not more than ? adcauline

length .. ee ae 84 ee Als ae is is S. m. asymmetrica

Sertularella mediterranea mediterranea Hartlaub, 1901

Fig. 96B—C

Diagnosis. Stem occasionally branched, reaching a maximum height of 34 mm,

but more often less than 20 mm; the two rows of hydrothecae in one plane.

Hydrotheca bilaterally symmetrical, with the two lateral marginal teeth

the same size, adnate for 2-3 adcauline height, 0,5-0,9 mm in abcauline height

and 0,19-0,4 mm in marginal diameter.

Variation. Branches, when they occur, show no uniformity in origin. They may

arise from below the hydrothecae, from the anterior surface of the stem or from

within the hydrothecae.

In the classical conception of the species the hydrotheca has a well developed

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 295

abcauline marginal tooth and a margin tilted towards the stem, but this is not

a constant character and in some colonies the teeth are of equal size and the

margin perpendicular to the axis, so that the perpendicular passes through the

hydropore or through the adcauline basal thickening, but never through the

adcauline wall as in the closely related S. natalensis. The width of the hydro-

thecal margin varies and occasional hydrothecae have particularly narrow

mouths. The three internal teeth of South African specimens are very constant

in size and position; sometimes two minute extra ones occur, one on each side

of the abcauline one. In only one hydrotheca of one colony were four internal

teeth seen, the abcauline tooth being replaced by two small ones. Variation in

the number of internal teeth has been reported for specimens from the

Mediterranean and other areas.

Distribution outside South Africa. Mediterranean and Red Sea, east coast of

Atlantic as far south as the Vema Seamount and Angola with scattered reports

from the Indian Ocean and Australasia. Type locality: Rovigno.

Distribution in South Africa. West coast of Cape Peninsula to Natal, littoral to

73 m. 33/18 (1), 34/18 (s), 34/23 (s), 33/25 (s), 30/30 (1), 29/31 (1, s), 28/32 (s)

Sertularella mediterranea asymmetrica Millard, 1958

Fig. 96A

Sertularella mediterranea, var. asymmetrica Millard, 1958: 191, fig. 7B.

Diagnosis. Stem unbranched, reaching a maximum height of 14 mm, the two

rows of hydrothecae not in one plane but shifted on to anterior surface.

Hydrotheca not bilaterally symmetrical but with one of the lateral marginal

teeth distinctly longer than the other, smaller and less adnate than the nominate

subspecies, adnate for 4-2 adcauline height, 0,3-0,6mm in abcauline height

and 0,14-0,2 mm in marginal diameter.

Female gonotheca with external marsupium.

Distribution. Endemic to South Africa. Type locality: Inhaca Island, Delagoa

Bay, littoral.

Distribution in South Africa. South coast from Mossel Bay to East London and

Inhaca Island, littoral to 46 m. 34/22 (1), 33/27 (s), 26/32 (1, s)

Sertularella megista Stechow, 1923

Fig. 97A—D

Sertularella megista Stechow, 1923b: 111. Stechow, 1925a: 480, fig. 36. Millard, 1957: 217,

figs 10L, 11J. Millard, 1964: 45. Millard, 1967: 180, fig. 4D.

Diagnosis. Stem moderately stiff (just able to support itself out of fluid), unfas-

cicled or lightly fascicled at base, unbranched or giving off a few long branches

at irregular intervals, reaching 140 mm in height. Branches arising from

immediately below hydrothecae, the two rows in one plane. Stem and branches

296 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 96.

Sertularella mediterranea. A, subsp. asymmetrica, hydrothecae; B, nominal subsp.,

hydrothecae; C, nominal subsp., male gonotheca.

Sertularella natalensis. D, gonotheca; E, hydrotheca; F, part of stem.

Sertularella pulchra. G, hydrothecae; H, gonotheca; J, stem.

Scale: J in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 297

divided into short internodes by oblique nodes sloping in alternate directions, but

nodes indistinct in older parts; each internode bearing one hydrotheca.

Hydrotheca large, with thick perisarc, adnate for $-? adcauline length,

smooth, adcauline wall bent sharply outwards at top of adnate part, margin

more or less perpendicular to axis, free part of adcauline wall straight or con-

cave, never convex; 0,8-1,9 mm in abcauline height and 0,3-0,6 mm in marginal

diameter. No internal teeth.

Gonothecae borne on stem or branches on the same level as, and on the

opposite side to, the base of the hydrotheca, spindle-shaped, with about five

rounded annulations; margin with three or four pointed spines.

Variation. Individual stems and branches of this species are easily recognized,

though the form of the colony as a whole varies. There is a tendency to produce

long unfascicled and unbranched stems or sections thereof. This is possibly

characteristic of sheltered waters, whereas shorter, fascicled, and more branched

colonies may be characteristic of exposed waters.

The shape of the hydrotheca varies between two extremes; one which is

adnate for over half the length and with a comparatively short free portion,

and one where the free part is much produced and may be twice as long as the

adnate part (forma e/ongata). In the latter the free part has practically parallel

walls but the mouth is no narrower than in the normal form.

Variation also occurs in the degree of bending in the adcauline wall,

and in the angle of the margin. A line drawn at right angles to the latter may

pass through the hydropore or through the adcauline wall. Rarely the free part

of the adcauline wall may be faintly corrugated.

The annulation of the gonotheca varies and may be more pronounced or

very indistinct.

Distribution outside South Africa. Vema Seamount. Type locality: Francis Bay,

South Africa, in 100 m.

Distribution in South Africa. All round coast from St. Helena Bay to Mocgam-

bique, 0-347 m. 32/18 (s), 33/18 (s), 34/18 (s), 34/21 (s), 36/21 (d), 34/22 (s),

34/23 (s, d), 34/24 (d), 33/25 (s), 34/25 (s, d), 33/26 (d), 34/26 (d), 33/27 (s),

32/28 (s), 33/28 (s), 30/30 (s), 30/31 (s, d), 29/31 (s, d), 29/32 (s), 28/32 (d),

24/35 (d)

Sertularella natalensis Millard, 1968

Fig. 96D-F

Sertularella natalensis Millard, 1968: 271, fig. 4E-G.

Diagnosis. Stem stiff, unfascicled, unbranched or with at most one branch,

reaching 34 mm in height, divided into internodes by oblique nodes sloping in

alternate directions, each internode bearing one hydrotheca. Branches similar to

stem.

Hydrotheca of medium size, adnate for 4-3 adcauline length, free part

298 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig: 97:

Sertularella megista. A, colony: B, hydrothecae; C, hydrotheca of forma elongata; D, male

gonotheca.

Sertularella striata. E, stem and hydrothecae; F, gonotheca.

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 299

directed outwards and narrowing to just below the margin, generally with one

to four vertical striations which start on free part of adcauline wall and run for

a varying distance parallel to adnate wall, 0,5-0,7 mm in abcauline height and

0,2-0,3 mm in marginal diameter. Margin tilted towards abcauline side. Five

or three internal teeth, one very large abcauline, two large latero-adcauline and

sometimes two minute latero-abcauline.

Gonothecae borne on stem opposite the bases of the hydrothecae, spindle-

shaped, annulated in distal half, with three or four marginal spines.

Variation. The striations on the hydrothecal wall are characteristic of the species

and always occur in some hydrothecae of a colony. They may be faint or absent

in other hydrothecae, particularly the older ones.

Distribution. Endemic to South Africa. Type locality: off Natal, 29°47,5’S/

31°12’E, 64 m.

Distribution in South Africa. Natal and Mocgambique, 1-64 m. 29/31 (s), 26/32

(s), 25/33 (s), 24/34 (s)

Sertularella polyzonias (Linnaeus, 1758)

Sertularia polyzonias Linnaeus, 1758: 813.

Sertularella polyzonias: Hincks, 1868: 235, pl. 46 (fig. 1). Hartlaub, 1901a: 88, pl. 1 (fig. 10),

pl. 5 (figs 2-5, 8). Broch, 1933: 65, fig. 24. Stechow, 1923c: 194, fig. D'c. Millard, 1957:

217, figs 10J, 11H.

Diagnosis. Stem unfascicled or weakly fascicled, flexuous and straggling (unable

to support itself out of fluid), irregularly branched. No obvious distinction

between main stem and branches. Branches arising from below hydrothecae,

often rebranched. Stem and branches divided into internodes by oblique nodes

sloping in alternate directions, each internode bearing one hydrotheca.

Hydrotheca adnate for about half adcauline length, smooth, with distal

half curved outwards and margin tilted towards abcauline side, abcauline wall

concave in distal half. Internal teeth generally absent, occasionally four minute

ones alternating with marginal teeth.

Gonothecae borne on stem and branches from immediately below hydro-

thecae, elongate-spindle-shaped, annulated at least in distal half; margin with

about four spines; female with external marsupium, larger than male.

Remarks. The discovery that S. xantha may sometimes possess four internal

teeth means that the distinction between this species and S. falsa, which always

possesses internal teeth, falls away. Both are regarded as subspecies of

S. polyzonias. The distinction between subsp. xantha and subsp. polyzonias (both

normally without internal teeth) is mainly one of size, the former having long,

weakly fascicled stems and larger hydrothecae, the latter having short, unfas-

cicled stems and smaller hydrothecae. S. polyzonias from other parts of the world

is known to vary greatly in size, though fascicled stems have as yet not been

reported.

300 ANNALS OF THE SOUTH AFRICAN MUSEUM

There is some doubt as to the exact nature of S. polyzonias, since the type

material has never been re-examined and described. The authorities quoted

above give a fair indication of the present-day concept of the species.

KEY TO SUBSPECIES

1. Four minute internal teeth present, alternating with the marginal teeth .. Sep. false

— No internal teeth dy 5 ae ee oe a a re

2. Hydrotheca very large, over 1 mm in abcauline height .. 8 é S. p. gigantea

— Hydrotheca small to medium, under 1 mm in abcauline height a ES

3. Stem often weakly fascicled, reaching great lengths (generally over 30 mm and up to

270 mm) - ioe ae ay a ae boys oF bee S. p. xantha

Stem never fascicled, short (generally under 30 mm, never exceeding 50 mm)

S. p. polyzonias

Sertularella polyzonias polyzonias (Linnaeus, 1758)

Fig. 98F—H

Diagnosis. Stem slender, unfascicled, short (usually under 30 mm, maximum

height 48 mm), unbranched or branching sparsely, with a tendency towards

stolon formation.

Hydrotheca small to medium, 0,3—0,6 mm in abcauline height and 0,18-

0,3 mm in marginal diameter. No internal teeth.

Gonotheca under 2,3 mm in length, with 3-6 marginal spines.

Variation. This is the most delicate of the four subspecies and is a common

epizooite of other hydroids. The stem varies considerably in length of internode;

it is sometimes geniculate and sometimes not, and often has a distinct annulation

immediately above each node. The two rows of hydrothecae are usually in one

plane, but sometimes shifted on to one surface.

The hydrotheca sometimes has the abcauline margin and marginal tooth

slightly produced so that a line drawn perpendicular to the margin passes

through the adcauline basal thickening instead of through the adcauline wall,

thus approaching S. africana. Occasionally vague transverse corrugations occur,

as are also characteristic of the latter species. These variations, however, are

seen only in isolated hydrothecae of a colony. The width of the mouth is variable

within a colony.

Distribution. Cosmopolitan, mainly North Atlantic. Type locality: U.K.

Distribution in South Africa. Table Bay to Mocambique, littoral to 111 m.

33/18 (s), 34/18 (1, s), 34/20 (s), 34/22 (s), 34/23 (s, d), 33/25 (s), 34/25 (s), 33/26

(s), 33/27 (s), 32/28 (s), 30/30 (s), 29/31 (s), 28/32 (s, d), 24/34 (s)

Sertularella polyzonias falsa Millard, 1957

Fig. 98D-E

Sertularella falsa Millard, 1957: 211, figs 10F, 11D.

Diagnosis. Stem unfascicled, short (under 30 mm), branching irregularly.

Hydrotheca small to medium, 0,4-0,6 mm in abcauline height and 0,19-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 830]

0,3 mm in marginal diameter. Four small internal teeth present, alternating with

marginal teeth.

Gonotheca of medium size (reaching 2,6 mm in length), with 3-4 marginal

spines.

Variation. This subspecies is very similar to.the nominal one in appearance and

dimensions, its main diagnostic character being the presence of internal teeth.

These may not be visible in older hydrothecae. S. polyzonias f. glabra Broch,

1933 is also described as having internal teeth in most of the hydrothecae, but

the shape of the hydrotheca is rather different, being more constricted at the

margin. As in the nominal subspecies the abcauline margin and marginal tooth

may be slightly produced so that the perpendicular passes through the adcauline

basal thickening. The abcauline wall may have a low thickening below the

margin.

Distribution. Endemic to South Africa. Type locality: False Bay, about a

kilometre east of Seal Island, 27 m.

Distribution in South Africa. False Bay and Knysna Estuary, littoral to 40 m.

34/18 (1, s), 34/23 (s)

Sertularella polyzonias gigantea Hincks, 1874

Fig. 98J

Sertularella polyzonias var. gigantea Hincks, 1874: 151, pl. 7 (figs 11-12). Stechow, 1925a:

478, fig. 6.

Diagnosis. Stem ?unfascicled, ?unbranched, reaching 17 mm in height, with one

or two weak annulations at the base of each internode. Perisare very thick in

stem, thin in hydrothecae.

Hydrotheca very large, 1,2 mm in abcauline height and 0,5 mm in marginal

diameter, adnate for about one-third height. No internal teeth.

Distribution outside South Africa. Uncertain. Type locality: Iceland.

Distribution in South Africa. One record only (Stechow 1925a), from Plettenberg

Bay, 100 m. 34/23 (d)

Remarks. No further material resembling that ascribed by Stechow to var.

gigantea has been found. Since Stechow’s description was based on one infertile

stem only, the nature of the colony cannot be diagnosed with certainty. It is also

not certain whether var. gigantea of Hincks is synonymous with S. gigantea

Mereschkowsky, 1878.

Sertularella polyzonias xantha Stechow, 1923

Fig. 98A—C

Sertularella xantha Stechow, 19736: 109. Stechow, 1925a: 472, fig. 32. Millard, 1957: 218,

figs 10K, 111.

Sertularella longa Stechow, 1923b: 110. Stechow, 1925a: 483, fig. 38.

Diagnosis. Stem often weakly fascicled at base, reaching great lengths (up to

302 ANNALS OF THE SOUTH AFRICAN MUSEUM

wate

Fig. 98.

Sertularella polyzonias. A-C, stem, hydrothecae and gonotheca of subsp. xantha; D and E,

hydrothecae and gonotheca of subsp. falsa; F-H, colony, hydrothecae and gonotheca

of subsp. polyzonias; J, hydrothecae of subsp. gigantea, redrawn from Stechow (1925a).

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 303

270 mm), branching and rebranching repeatedly. Internodes often very long and

nodes not visible in older regions.

Hydrotheca of medium size, adnate for over half height, 0,5-0,7 mm in

abcauline height and 0,2-0,3 mm in marginal diameter. Usually without internal

teeth.

Gonotheca long, over 2,5 mm, with 3-4 marginal spines.

Variation. In this subspecies it is only the older colonies which have fascicled

stems, and even these always retain the slender and flexuous appearance typical

of the species. In some colonies the branching may show a tendency towards a

regular pinnate arrangement, but it is more often quite irregular. Both inter-

node length and thickness of perisarec vary tremendously, young parts of the

colony having short internodes, thin perisarc and distinct nodes, and older parts

having longer internodes, thicker perisarc and no nodes. With thicker perisarc,

a thickening on the abcauline wall of the hydrotheca is apparent, which, how-

ever, 1S never so marked as, for instance, in S. arbuscula.

The hydrorhiza, which is typically creeping, may become branching and

filamentous in deep-water specimens for penetration of mud.

In the hydrotheca the perpendicular always passes through the adcauline

wall, though the concavity in the abcauline wall may at times be very slight.

Usually there is no sign of internal teeth, but certain stems in a colony may have

four minute internal teeth alternating with the marginal teeth.

Distribution. Endemic to South Africa. Type locality: off Cape Town, 33°41,2’S/

18°0;3E, 178 m.

Distribution in South Africa. Common on the south coast from Table Bay to

East London, also off Durban, 7-350 m. 33/18 (s, d), 34/18 (s, d), 35/19 (s),

34/20 (s), 34/21 (s), 35/21 (d), 34/22 (s, d), 35/22 (d), 34/23 (s, d), 34/24 (d),

33/25 (s), 34/25 (d), 34/26 (d), 33/27 (s), 29/31 (s, d)

Sertularella pulchra Stechow, 1923

Fig. 96G-J

Sertularella pulchra Stechow, 1923b: 113. Stechow, 1925a: 485, fig. 39. Millard, 1964: 46,

fig. 13E-G.

Diagnosis. Stem stiff, fascicled, giving off alternate hydrocladia in one plane,

reaching 74 mm in height. Hydrocladia arising from immediately below every

third hydrotheca at a wide angle, alternately on the right and left. Stem and

hydrocladia divided into internodes by oblique nodes sloping in alternate direc-

tions, each internode bearing one hydrotheca.

Hydrotheca of medium size, long and slender, adnate for about half

adcauline length, with three or four distinct transverse striations on free part of

adcauline wall, abcauline wall straight or slightly concave, margin perpendicular

to axis or tilted slightly towards abcauline side, 0,6-0,8 mm in abcauline height

304 ANNALS OF THE SOUTH AFRICAN MUSEUM

and 0,2-0,3 mm in marginal diameter. Four internal teeth of equal size alternating

with marginal teeth.

Gonothecae borne on stem and hydrocladia immediately below the hydro-

thecae on the same or the opposite side, spindle-shaped, annulated; margin with

4-6 spines.

Variation. The long, slender hydrotheca with adcauline striations is characteristic

and easily recognized. Usually the axis is straight, but sometimes it is slightly

curved. In general the tendency is to bend away from the stem, but occasional

examples occur in which the abcauline marginal tooth is slightly elongated so that

the perpendicular passes through the hydropore. The adcauline striations are

occasionally faint or invisible, though only in a few hydrothecae of a colony.

The internal teeth are constant in number and position, though occasionally

absent in the youngest hydrothecae of a colony or in very young stems with

extra thin perisarc.

Distribution. Endemic to South Africa. Type locality: Simon’s Bay, 70 m.

Distribution in South Africa. South coast, from False Bay to East London, 40-

120 m. 34/18 (s), 34/21, 34/23 (s), 34/25 (s), 33/26 (d), 33/27 (s), 33/28 (s), 32/28 (s)

Sertularella striata Stechow, 1923

Fig. 97E-F

Sertularella striata Stechow, 1923a: 10. Stechow, 1925a: 470, fig. 30. Millard, 1964: 47, fig. 15.

Diagnosis. Stem short and stiff, unfascicled, unbranched or with at most one

or two short branches, reaching 11 mm in height. Branches, when present, arising

from immediately below the hydrothecae. Stem and branches divided into inter-

nodes by oblique nodes sloping in alternate directions, each internode bearing

one hydrotheca and usually with an annulation at the base.

Hydrotheca small, adnate for about half adcauline length, with about six

or seven distinct, ridged annulations evenly spaced over entire length and con-

tinued right round wall, abcauline wall more or less straight, abcauline marginal

tooth generally produced and margin perpendicular to axis or tilted slightly

towards adcauline side, 0,4-0,5 mm in height and 0,15-0,2 mm in marginal

diameter. No internal teeth.

Gonothecae borne on front of stem immediately below the hydrothecae,

spindle-shaped, annulated; margin generally with three or four minute spines.

An external marsupium present in female.

Variation. The hydrotheca is characteristically asymmetrical in side view with

the abcauline tooth produced, but a slight outward bend usually results in a

margin perpendicular to the axis. Occasionally, however, completely symmetrical

hydrothecae are found. The strength and number of the striations is variable,

and in the same colony examples may be found with about nine distinct striations

and others with only four or five rather indistinct ones, the former

predominating.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 305

The gonothecae tend to be completely annulated, though the striations may

fade out in the lower region. Marginal spines vary in number, and may be as

many as five or six.

Distribution. Endemic to South Africa. Type locality: Cape Agulhas, 35°2,5’S/

19°58,5’E, 80 m.

Distribution in South Africa. Agulhas Bank, from Cape Agulhas to East London,

9-100 m. Not common. 35/19 (s), 34/22 (s), 34/23 (d), 33/25 (s), 33/27 (s)

Doubtful species

Sertularella gayi (Lamouroux, 1821)

Sertularia gayi Lamouroux, 1821: 12, pl. 66 (figs 8-9).

Sertularella gayi: Picard, 1956: 261, figs 2d, 4a. Vervoort, 1959: 273, figs 33b-c, 34b. Ralph,

1961a: 833, fig. 24d-f. Vervoort, 19666: 127, fig. 30.

Remarks. Previous records of this species from South Africa are as follows:

Johnston (1838) as Sertularia polyzonias var. 8. This material was ascribed to S. gayi

by Hincks (1868) and Nutting (1904). Diagram and description inadequate.

Busk (1851) as Sertularia polyzonias. An infertile stem of Busk’s material was ascribed

to S. gayi by Millard (1961) but the hydrotheca was without adcauline annula-

tions and might equally well be S. dubia.

Jaderholm (1923a). An infertile fragment. No diagram given.

None of these records is conclusive evidence that the species occurs in South

Africa. Picard (1956) maintains that S. gayi can be distinguished from closely related

species by the bilabiate aperture of the gonotheca. Infertile material could be confused

with S. capensis or S. dubia, in which the margin of the gonotheca bears several

minute spines.

S. gayi is common in the Atlantic and has been reported from tropical west Africa

by Vervoort (1959, 1966). It might be noted that some of Vervoort’s material is with-

out the characteristic annulations on the adcauline wall of the hydrotheca, thus

approaching the condition in S. dubia.

Genus Sertularia Linnaeus, 1758

Diagnosis. Stem erect, branched or unbranched. Stem and branches bearing

hydrothecae in two longitudinal rows. Hydrotheca sessile, partly adnate, with

two marginal teeth seated more or less midway between adcauline and abcauline

edge and usually a small, median adcauline one. Aperture triangular. Operculum

of two valves, a smaller adcauline one and a larger abcauline one, the former

often divided into two sections by a median partition. Hydranth with an

abcauline caecum.

Type species: Sertularia cupressina Linnaeus, 1758.

KEY TO SPECIES

[Doubtful species not included, for these see p. 313]

1. Stem normally branching, branches alternate. Hydrotheca with abcauline intrathecal

septum a ne Me a 5 oe a oe oe S. marginata

— Stem normally unbranched; if branched, branches not alternate

306 ANNALS OF THE SOUTH AFRICAN MUSEUM

2. Hydrotheca with abcauline intrathecal septum .. ie BE a ey See 3)

— Hydrotheca without intrathecal septum .. 4

3. Hydrotheca erect and only slightly bent out in distal region. Merce es ine ae

poorly developed Aes S. ligulata

— Hydrotheca strongly bent out at about half height Marginal t teeth usually triangular

and well developed .. a 5 : : 5 ate S. turbinata

4. Hydrotheca bulging near base and narrowing saenediy to margin. Perisarc thickened

around thecal margin : S. longa

- Hydrotheca slender, with more or “Tess parallel sides, ‘narrowing only slightly to

margin. Perisarc of hydrotheca not thickened .. a me Ay .. 9S. distans

Sertularia distans (Lamouroux, 1816)

Fig. 99E-H

Dynamena distans Lamouroux, 1816: 180, pl. 5 (fig. 1).

Sertularia gracilis Hassall, 1848: 2223. Hincks, 1868: 262, pl. 53 (fig. 2).

Sertularia heterodonta Ritchie, 1909: 79, fig. 4.

Sertularia distans: Billard, 19256: 197, fig. 1.

Sertularia distans var. gracilis: Billard, 1925a: 175, fig. 33. Millard, 1957: 221, fig. 12. Van

Germerden-Hoogeveen, 1965: 36.

Sertularia distans gracilis: Millard, 1964: 49.

Diagnosis. Stem unfascicled, unbranched, 3-12 mm in height, each normal inter-

node bearing a pair of opposite hydrothecae. Normal nodes straight. Hinge-

joints present (a) terminating basal athecate part of stem, and (b) sporadically

in distal region, each terminating a separate, narrow, athecate internode.

Members of a pair of hydrothecae contiguous in front (except occasionally in

basal part of stem), separate behind.

Hydrotheca tubular, not swollen and with more or less parallel sides in

basal part, narrowing slightly to margin, distal part bent outwards at an angle

of about 70° with stem, with evenly concave abcauline wall; adnate $-2 adcau-

line length; with no intrathecal septum, 0,19-0,3 mm in abeauline he gt and

0,07—0,09 mm in marginal diameter. Margin with two moderately well-developed

lateral teeth and a small adcauline one.

Gonotheca oval, smooth, circular in cross-section, with wide distal aperture

on a short collar, with external marsupium in female.

Variation. There seems to be little ground for specific, or even varietal, differen-

tiation between S. distans and S. gracilis, the differences noted by various authors

(Billard 19255; Picard 1951) being minor ones of size only. Thin etiolated stems

(said to be characteristic of S. distans) may occur in the same colony as thicker

stems (said to be characteristic of S. gracilis).

Regular branching does not occur, but occasional instances of branches

arising from within hydrothecae have been seen. Considerable variation in

growth-form can occur, including such characters as the presence or absence

of internal perisarcal thickenings in the hydrorhiza, the length of the basal

athecate part of the stem, the number of hinge-joints terminating this region

(1-3), the length of the thecate internodes, and the presence of nodes (which may

be indistinct or invisible). Variation may also occur along the length of a stem,

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 307

the distal pair of hydrothecae being more erect, longer, and contiguous with one

another for a greater length than the basal one.

Internal pegs of perisarc in the basal region of the hydrotheca are very

characteristic, although not invariably present. These include one on the abcau-

line wall near the base, and one on the base medial to the hydropore. Internal

teeth may also occur in the hydrotheca just below the margin—a single abcauline

tooth is common and usually well developed when present, and occasionally

two extra teeth may occur in a latero-adcauline position.

Distribution outside South Africa. Common in the tropical and temperate regions

of the Atlantic and Indian Oceans; also Japan. Type locality: Atlantic Ocean.

Distribution in South Africa. Present at numerous localities from False Bay to

Santa Carolina in Mocgambique, though not common inany one place, littoral

to 100 m. 34/18 (s), 34/20 (1), 34/22 (s), 33/25 (s), 33/27 (s), 32/28 (1, s), 31/29

(I, s), 31/30 @), 30/30 (Ss), 29/31 (s), 28/32 (s, d), 26/32 (1) 25/23 (s), 24/34 (s),

24/35 (s), 23/35 (s), 21/35

Sertularia ligulata Thornely, 1904

Fig. 100A, D

Sertularia ligulata Thornely, 1904: 116; pl. 2 (figs 1-1B). Billard, 1925a: 178, fig. 35 (early

synonymy). Leloup, 1937: 44, fig. 30. Millard, 1958: 193, figs 8C, 9A—B. Vervoort, 1959:

277, fig. 37. Millard & Bouillon, 1973: 74, fig. 9G.

Diagnosis. Stem unfascicled, usually unbranched but rarely with 1-3 branches,

reaching a height of 27 mm, with a short basal athecate part terminated by a

hinge-joint and a long distal part bearing hydrothecae in opposite pairs. Mem-

bers of a pair of hydrothecae contiguous in front, separate behind. Branches,

when present, similar to stem.

Hydrotheca with an abcauline intrathecal septum; swollen below septum,

narrowing to mouth above it; erect and parallel to stem for half or more of

height, then bent out; adnate for two-thirds or more of adcauline length, 0,2-

0,3 mm in abcauline height, 0,11-0,16 mm in marginal diameter. Margin very

delicate, more or less parallel to axis of stem, with two low and poorly developed

lateral teeth and a small adcauline one. No internal teeth. Adcauline opercular

flap very small. A leaf-shaped process, the ligula, present on adcauline side of

hydranth body, arising from base of hydranth and projecting through mouth of

hydrotheca when extended, well-armed with nematocysts and probably

functioning as a nematophore.

Gonotheca (not reported from South Africa) borne on stem below

hydrotheca, barrel-shaped, with about three transverse annulations (Thornely).

Variation. Branching, when it occurs, is not regularly alternate; the branches

arise from the front of the stem below the thecal pairs and slightly to one side,

they project diagonally forwards and the hydrothecae face towards the mid-line.

There is no disturbance of the arrangement of the cauline hydrothecae as, for

308 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 99.

Sertularia marginata. A, pinnate stem showing origins of hydrocladia and one rebranching

hydrocladium; B, pinnate stem; C, hydrothecae; D, simple stem.

Sertularia distans. E and F, hydrothecae from middle and lower parts of stem respectively,

F with hinge-joint; G, gonotheca; H, stem.

Scale: B in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 309

instance, in S. marginata. Stems and branches often form stolons which reattach

and result in a tangled colony. Branches may also arise from within the hydro-

thecae.

The stem nodes are variable. They may be absent, suggested only by a

shallow groove, or present and then straight or slightly oblique.

The hydrothecae change in shape along the length of the stem, the distal

ones being more erect, and contiguous and adnate for a greater amount than the

basal ones. The margin tends to be directed slightly upwards in the distal hydro-

thecae and slightly downwards in the basal ones.

Distribution outside South Africa. Tropical Indo-Pacific, tropical West Africa

and Japan. Type locality: Gulf of Manaar, Ceylon.

Distribution in South Africa. Mogambique: Inhaca to Santa Carolina, 0-15m.

26/32 (1, s), 23/35 (s), 21/35

Sertularia longa Millard, 1958

Fig. 10OF—H

Sertularia linealis var. longa Millard, 1958: 197, fig. 8E.

Sertularia linealis: Millard, 1968: 272.

Sertularia linealis longa: Millard & Bouillon, 1973: 75, fig. 9E-F.

Sertularia longa: Millard & Bouillon, 1974: 33, fig. 7D, J.

Diagnosis. Hydrorhiza usually growing on weed and with internal strengthening

pegs of perisarc. Stem unfascicled, unbranched, reaching a maximum height of

9 mm, each normal internode bearing a pair of opposite hydrothecae. Normal

nodes oblique or indistinct. A hinge-joint (or rarely, two) present near base of

stem below thecate part, and at irregular intervals within thecate part where it

terminates a short intermediate athecate internode. Members of a pair of hydro-

thecae contiguous in front (except sometimes in basal part of stem), separate

behind.

Hydrotheca adnate for over half height, bent outwards, swollen below

and narrowing to mouth, with concave abcauline wall but not evenly so and with

a definite kink in lower or middle part, with no intrathecal septum, 0,16—0,2 mm

in abcauline height and 0,07-0,11 mm in marginal diameter. Margin usually

thickened, with two well-developed, roundly triangular lateral marginal teeth

and a very small adcauline one. Internal teeth absent.

Gonotheca borne on front of stem below first pair of hydrothecae, smooth,

compressed, curved pear-shape in broad view, with a wide distal operculate

aperture on a short collar, reaching 1,1 mm in length and 0,6 mm in maximum

diameter.

Variation. The shape of the hydrotheca changes along the length of the stem,

the distal ones being more erect and contiguous for a greater length than the

proximal ones.

Distribution outside South Africa. Seychelles.

310 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 100.

Sertularia ligulata. A, stem; D, hydrotheca with hydranth, showing caecum, ligula and

operculum (broken line).

Sertularia turbinata. B, forma acuta, stem; C, forma turbinata, stem; E, forma acuta,

gonotheca.

Sertularia longa. F, hydrotheca; G, stem; H, stem with gonotheca.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 311

Distribution in South Africa. Coast of Mogambique, littoral to 42 m. Type

locality: Inhaca Island. 26/32 (1, s), 25/32, 25/33 (s), 23/35 (1)

Sertularia marginata (Kirchenpauer, 1864)

Fig. 99A—D

Dynamena marginata Kirchenpauer, 1864: 13, fig. 8.

Desmoscyphus inflatus Versluys, 1899: 42, figs 11-13.

Sertularia marginata: Billard, 1925a: 178. Totton, 1930: 204, fig. 48b. Millard, 1957: 224,

fig. 13. Ralph 196la: 785, fig. 12a-g. Van Germerden-Hoogeveen, 1965: 39, figs 13-17.

Mammen, 1965a: 45, fig. 77. Millard & Bouillon, 1974: 33, fig. 6E.

Sertularia inflata: Vervoort, 1959: 281, figs 39-41. Van Gemerden-Hoogeveen, 1965: 45,

figs 18-22.

Diagnosis. Stem unfascicled, reaching a height of 30 mm, either pinnate, or

simple and unbranched. Pinnate stem with a short basal athecate part terminated

by a hinge-joint, and a long distal thecate part bearing alternate hydrocladia.

Thecate part divided by oblique nodes into internodes which bear either one

hydrocladium and three hydrothecae (one in axil and an alternate pair above),

or one pair of opposite or subopposite hydrothecae. Stem geniculate at least

in distal part. The two rows of hydrocladia in one plane. Members of a pair of

hydrothecae not contiguous except in distal region of stem.

Hydrocladium borne on long apophysis of stem and separated from it by

a hinge-joint. Apophysis containing a transverse node which may be indistinct.

Hydrocladium divided by nodes, which vary from very distinct and oblique to

indistinct and transverse, into internodes, each of which bears a pair of opposite

hydrothecae on anterior surface. Members of a pair of hydrothecae contiguous

in front (except sometimes in basal region of hydrocladium), separate behind.

Simple stem similar to hydrocladium.

Hydrotheca with an abcauline intrathecal septum, swollen below septum,

narrowing to mouth above it, bent outwards and slightly forwards, adnate for

over half adcauline length, 0,15-0,3 mm in abcauline height, 0,09-0,19 mm

in marginal diameter. Margin with two well-developed, triangular and sharp

lateral teeth and a small adcauline one. No internal teeth.

Gonotheca (not reported from South Africa) borne on front of stem, ovate,

compressed, with 5-9 transverse ridges, terminal opening and two distal spines.

Variation. The hydrorhiza may contain internal perisarcal thickenings in certain

regions.

The basal athecate part of the stem is of variable length and may contain

one or more transverse nodes. The arrangement on the rest of the stem

depends on the presence or absence of hydrocladia. Aninternode bearing a hydro-

cladium typically has three hydrothecae arranged as described above, and an

internode without a hydrocladium typically has a pair of opposite hydrothecae.

When the first condition changes to the second the hydrothecae on successive

internodes are gradually displaced from the alternate to the opposite position,

and vice versa. A varying number of thecate internodes (up to four) without

312 ANNALS OF THE SOUTH AFRICAN MUSEUM

branches may occur at the proximal and the distal end of a branching stem and

occasionally at intervals along its length. Hydrocladia are normally unbranched,

but may branch in a similar way to the stem, with the same modifications.

Hinge-joints may occasionally occur in the thecate part of the stem, but are

not so common as in certain other species (e.g. S. distans). Such a hinge-joint

always forms the termination of a short, intermediate, athecate internode.

In unbranched regions of the stem or hydrocladia the amount of contiguity

between members of a pair of hydrothecae is variable and tends to increase

towards the distal end. This is particularly well shown in simple stems, where

the proximal pairs usually do not touch one another at all. The structure of the

hydrotheca shows a similar gradation, those at the distal end being more erect

than the proximal ones and without the intrathecal septum.

Distribution outside South Africa. Common in all tropical oceans, and extending

into temperate areas in the Atlantic and southern Pacific (New Zealand).

Type locality: Pacific Ocean.

Distribution in South Africa. False Bay to Inhaca, 0-46 m. Not common.

34/18 (s), 34/25 (s), 26/32 (s)

Sertularia turbinata (Lamouroux, 1816)

Fig. 100B-C, E

Dynamena turbinata Lamouroux, 1816: 180.

Sertularia loculosa: Warren, 1908: 306, fig. 8, pl. 48 (fig. 37).

Tridentata acuta Stechow, 1921b: 231.

Sertularia turbinata: Billard, 1925a: 177, fig. 34. Millard, 1958: 197, fig. 8B. Vervoort, 1959:

275, figs 35-36. Millard, 1964: 49. Millard & Bouillon, 1973: 76, fig. 9H.

Sertularia acuta: Millard, 1958: 192, fig. 8A, F.

Diagnosis. Stem unfascicled, unbranched, reaching a height of 25 mm, with a

short basal athecate part terminated by a hinge-joint and a long distal part

bearing hydrothecae in opposite pairs. Hinge-joints also occurring sporadically

in distal region, each forming the termination of an extra, narrow, athecate

internode. Members of a pair of hydrothecae contiguous in front (except some-

times in basal region of stem), separate behind.

Hydrotheca with an abcauline intrathecal septum, swollen below septum,

narrowing to mouth above it, curved outwards and members of a pair with

their axes diverging progressively from base to margin, adnate for 4-3 adcauline

length, 0,16-0,3 mm in abcauline height, 0,09-0,17 mm in marginal diameter.

Margin usually facing upwards and outwards, with two well-developed,

triangular lateral teeth and a small adcauline one. No internal teeth.

Gonotheca borne on stem below hydrothecae, barrel-shaped, annulated,

with wide distal aperture.

Variation. This species occurs in two forms, which were originally considered to

be separate species but which have been shown (Millard 1964) to grade into one

another.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 313

Forma turbinata (Lamx.) has long internodes (approx. 0,8 mm) and long

hydrothecae (abcauline length approx. 0,3 mm) and the nodes are generally

oblique. Forma acuta (Stechow) has short internodes (approx. 0,5 mm) and

short, squat hydrothecae (abcauline length approx. 0,2 mm) and the nodes are

generally straight. In both forms the nodes may be indistinct in the lower part

of the stem. ;

The shape and position of the hydrotheca changes along the length of the

stem—the members of the distal pair being more erect and more contiguous to

one another than those of the proximal pair.

The perisarc is thin in young colonies, though with a tendency for thickening

of the abcauline thecal wall distal to the intrathecal septum. In old colonies all

the perisarc is thickened.

Vervoort has observed two minute distal spines on the gonotheca of

f. turbinata; these have not been seen in f. acuta.

Distribution outside South Africa. Circumglobal in tropical and subtropical

waters. Type locality: Australasia.

Distribution in South Africa. Mossel Bay on the south coast to Inhambane on the

east, littoral to 48 m. 34/22 (s), 33/27 (s), 31/29 (1), 30/30 (1), 29/31 (s), 28/32

(s), 26/32 (1), 24/35 (s), 23/35 (1, s)

Doubtful species

Sertularia argentea Linnaeus, 1758

Sertularia argentea Linnaeus, 1758: 809. Busk, 1851: 118. Hincks, 1868: 268, pl. 56. Hancock

et al., 1956: 307, figs 1E-H, 2A-B, D-E, 3, 5. Millard, 1961: 203.

Remarks. This common North Atlantic species has only been recorded from South

Africa by Busk (1851). The identification of Busk’s material was confirmed by Millard

(1961), but the species has never been found again. Its presence in South African

waters needs confirmation.

Genus Stereotheca Stechow, 1919

Syn. Levinsenia Bale, 1915.

Diagnosis. Stem erect, unfascicled, pinnate. Stem and hydrocladia bearing two

longitudinal rows of hydrothecae. Hydrotheca sessile, with more than four well-

developed marginal teeth, with no intrathecal septa and no external ridges or

furrows. No operculum.

Type species: Sertularia elongata Lamouroux, 1816.

One species only from South Africa.

Stereotheca elongata (Lamouroux, 1816)

Fig. 101D, E

Sertularia elongata Lamouroux, 1816: 189, pl. 5 (fig. 3). Allman, 1886: 140, pl. 15.

Stereotheca elongata: Ralph, 1961a: 762, fig. 4e—k.

Diagnosis. Stem moderately stiff (able to support itself out of fluid), unfascicled,

314 ANNALS OF THE SOUTH AFRICAN MUSEUM

unbranched, reaching 58 mm; bearing alternate hydrocladia; divided into regular

internodes by oblique nodes sloping in alternate directions. Each internode

bearing one hydrocladium and three hydrothecae (one axillary and a subopposite

pair above). The two rows of hydrocladia in one plane. Hydrocladium borne on

a short apophysis; divided into internodes of irregular length by slightly oblique

nodes; each internode bearing one to three pairs of subopposite hydrothecae.

The two rows of hydrothecae in one plane.

Hydrotheca tubular, with axis straight or bent outwards, adnate for over

three-quarters of adcauline height, smooth, 0,2-0,3 mm in abcauline height

and 0,14-0,20 mm in marginal diameter. Margin with six teeth which are very

irregular in size, shape and position.

Gonotheca borne on stem immediately below third hydrotheca of inter-

node, smooth, compressed, widening from base to truncated distal end, which

bears a terminal aperture on a short collar and two hollow spines.

Variation. Much variation occurs in the shape of the hydrotheca and its marginal

teeth. The hydrotheca is usually asymmetrical, bending slightly to one side,

and there may also be an asymmetry of the teeth, with those of one side better

developed than those of the other. One marginal tooth may be very

much broader and longer than the others.

The distal horns of the gonotheca are also reported to vary in length, though

not noticed in South Africa; they are usually long, though one or both may be

reduced to short knobs.

Distribution outside South Africa: Australasia (type locality), North Sea.

Distribution in South Africa. Algoa Bay. 33/25

Genus Symplectoscyphus Marktanner-Turneretscher, 1890

Diagnosis. Stem erect, branched or unbranched. Stem and hydrocladia bearing

alternate hydrothecae which form two longitudinal rows. Hydrotheca sessile,

generally more cylindrical than in Sertularella, with three marginal teeth, one

median adcauline and two latero-abcauline, and an operculum of three triangular

valves seated in the bays between the teeth and meeting in the centre as a

pyramid. Hydranth with abcauline caecum.

Type species: Symplectoscyphus australis Marktanner-Turneretscher, 1890

(= Sertularia johnstoni Gray, 1843).

KEY TO SPECIES

(Doubtful species not included. For these see p. 319)

1 Hydrotheca large (over 0,7 mm in abcauline height), tubular, curved smoothly outwards.

Distal part of stem slender and geniculate S. paulensis

- Hydrotheca small to medium (under 0,7 mm in abcauline height). Stem not geniculate 2

2; Stem fascicled and freely branching. Hydrotheca with wide mouth (= half or more ab-

cauline length). Gonotheca annulated - a & — S. arboriformis

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 315

Fig. 101.

Symplectoscyphus arboriformis. A, hydrotheca; B, stem, C, hydrocladium and gonotheca.

Stereotheca elongata. D, part of stem showing origins of hydrocladia and gonotheca;

E, hydrotheca.

Scale: B in cm, the rest in mm/10.

316 ANNALS OF THE SOUTH AFRICAN MUSEUM

— Stem unfascicled, usually unbranched. Hydrotheca with narrow mouth (= half or less

abcauline length) a os ce as By ts ie ce ne wre 8)

3. Gonotheca smooth, aperture on slender neck... Le ae S. macrogonus

— Gonotheca transversely annulated, no neck a 3s ms ba S. secundus

Symplectoscyphus arboriformis (Marktanner-Turneretscher, 1890)

Fig. 101A—C

Sertularella arboriformis Marktanner-Turneretscher, 1890: 228, pl. 4 (fig. 5). Stechow, 1912:

Sioa arboriformis: Millard, 1964: 51.

Diagnosis. Stem stiff, fascicled, branching and rebranching in a roughly alternate

fashion and in one plane, reaching 110 mm in height. Hydrocladia arising from

below hydrothecae, the two rows in one plane. Stem and hydrocladia divided

into internodes by oblique nodes sloping in alternate directions, each internode

bearing one hydrotheca. The two rows of hydrothecae in one plane.

Hydrotheca small to medium, adnate for 4-4 adcauline length, smooth,

curved outwards and margin tilted towards abcauline side, 0,3-0,6 mm in

abcauline height and 0,3-0,4 mm in marginal diameter. Margin not constricted.

No internal teeth.

Gonothecae borne on stem and hydrocladia immediately below the hydro-

thecae, obovoid, transversely annulated in distal part, reaching 1,9 mm in

height and 1,0 mm in maximum diameter. Aperture small and circular, on a

raised collar.

Distribution. Endemic to South Africa. Type locality: ‘Indian Ocean’.

Distribution in South Africa. From the Orange River mouth in the west to Natal

in the east, 10-219 m. 28/16 (s), 33/18 (s), 34/18 (s), 34/21 (s), 35/21 (d), 34/22,

35/22 (d), 33/25 (s), 34/25 (s, d), 33/26 (d), 34/26 (d), 33/27 (s), 33/28 (s),

32/28(s), 29/311 @)

Symplectoscyphus macrogonus (Trebilcock, 1928)

Fig. 102D-—G

Sertularella macrogona Trebilcock, 1928: 11, pl. 1 (figs 44d).

Symplectoscyphus macrogonus: Millard, 1957: 219. Ralph, 1961a: 798, fig. 14a—b.

Diagnosis. Stem stiff, unfascicled, generally unbranched, reaching 32 mm in

height, but usually under 10 mm. Stem divided into internodes by oblique nodes

sloping in alternate directions, each internode bearing one hydrotheca. The two

rows of hydrothecae usually shifted onto anterior surface.

Hydrotheca small, adnate for less than half adcauline length, smooth,

tubular, curved outwards and then upwards, 0,2-0,3 mm in abcauline height

and 0,09-0,15 mm in marginal diameter; margin perpendicular to axis or tilted

towards abcauline side; abcauline wall straight or concave. Three internal

teeth usually present alternating with marginal teeth.

Gonotheca borne near base of stem, smooth, compressed, obovoid in

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 317

broad view, with a broad, concave distal end from the centre of which arises

a slender collar bearing a terminal aperture, reaching 1,4 mm in length and

1,1 mm in maximum diameter.

Colour: stem horn-coloured, hydranths creamy white.

Variation. This species commonly grows on weeds, and its appearance varies

from a sparse carpet of unbranched stems to a bushy growth of irregularly

branched and anastomosing stems. The two rows of hydrothecae sometimes lie

in the same plane, but more often they form an angle between them which may

be as small as 45°. At the base of the stem are two or more close annulations.

Internal teeth may be absent in complete stems of a colony or in just some

hydrothecae of a stem.

Distribution outside South Africa. New Zealand, tropical South West Africa.

Type locality: Dunedin, New Zealand.

Distribution in South Africa. From the northern border of South West Africa

to East London, common on the west coast, littoral to 37 m. 20/13 (1), 26/15

(28/16 (S), 32/17 (1); 32/18 (1, s), 33/17 G), 33/18 dC, s), 34/18 d, s),; 34/19,

Bo s1(S)2 93) 261(1), 33/27 (1); 32/28 (s)

Symplectoscyphus paulensis Stechow, 1923

Fig. 102A—C

Symplectoscyphus paulensis Stechow, 1923a: 8. Stechow, 1925a: 467, fig. 28. Millard, 1967:

183, fig. 4G—H. Vervoort, 1972: 180, figs 60b, 61.

Diagnosis. Stem moderately stiff, generally unfascicled, unbranched or with

one or two alternate branches, reaching a maximum height of 47 mm. Stem

divided into internodes by oblique nodes sloping in alternate direttions (but

nodes often indistinct), each internode bearing one hydrotheca, geniculate and

very slender in distal regions. The two rows of hydrothecae and branches in one

plane.

Hydrotheca large, adnate for one-third or less adcauline length, smooth,

tubular, curved outwards, not narrowing to margin, 0,7-0,9 mm in abcauline

height and 0,4 mm in marginal diameter. No internal teeth. A pair of oval

fenestrae closed by thin perisarc present below the base of each hydrotheca.

Gonothecae borne on stem or branches, obovoid, with several transverse

undulations and a terminal aperture on a slender collar, reaching 1,5 mm in

length and 1,1 mm in maximum diameter.

Variation. Stechow described this species as having a strongly fascicled stem,

but South African material is at most lightly fascicled in the larger stems only.

Possibly more mature colonies are more strongly fascicled.

Many of the hydrothecae have a thickened rim around the margin.

Distribution outside South Africa. South-west Indian Ocean and South Atlantic.

Type locality: east of St. Paul, Indian Ocean.

318 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 102.

Symplectoscyphus paulensis. A, hydrotheca; B, fertile stem; C, part of stem with gonotheca.

Symplectoscyphus macrogonus. D, female gonotheca; E, stem and male gonotheca; F and

G, hydrothecae.

Symplectoscyphus secundus. H, hydrothecae and gonotheca, redrawn from Kirchenpauer

(1884, as Sertularella secunda).

Scale: B in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 319

Distribution in South Africa. Off Natal and Mogambique in 347-440 m. A deep-

water species. 29/31 (d), 24/35 (d)

Symplectoscyphus secundus (Kirchenpauer, 1884)

Fig. 102H

Sertularella secunda Kirchenpauer, 1884: 50, pl. 15 (figs 7—7a). Hartlaub, 1901a: 75, pl. 2

38).

Res tnbia ees 1886: 134, pl. 9 (figs 3-4).

Diagnosis. Stem unfascicled, unbranched or weakly branched, reaching 7 mm

in height, divided into short internodes by oblique nodes sloping in alternate

directions, each internode bearing one hydrotheca. The two rows of hydrothecae

not in one plane but shifted onto the anterior surface of the stem.

Hydrotheca small, adnate for less than one-third length, smooth, flask-

shaped, 0,3-0,4 mm in abcauline height and 0,17—0,2 mm in marginal diameter;

margin tilted towards adcauline side due to elongation of abcauline marginal

tooth; abcauline wall more or less straight. Three internal teeth sometimes

present, alternating with marginal teeth.

Gonothecae borne on stem, ovoid to spherical, with a few transverse

annulations in distal half; aperture terminal, without neck; with external

marsupium.

Remarks. This species has not been recorded since the time of Kirchenpauer and

Allman. The type material was redescribed by Hartlaub.

The measurements given in the diagnosis were taken from Allman’s material

in the British Museum. The internal teeth were observed in this material,

although not mentioned in the literature. The species is very similar to

S. macrogonus, but has a different gonotheca.

Distribution. Endemic to South Africa.

Distribution in South Africa. Both Kirchenpauer and Allman give the locality

simply as Cape of Good Hope.

Doubtful species

Symplectoscyphus filiformis (Allman, 1888)

Sertularia gracilis Allman, 1888: 51, pl. 24 (figs 1—-1a).

Sertularia filiformis Allman, 1888: pl. 24 (figs 11a).

Sertularella filiformis var. reticulata Ritchie, 1907b: 535.

Symplectoscyphus filiformis: Totton, 1930: 194, fig. 42, pl. 3 (fig. 9). Rees & Thursfield, 1965:

129.

Remarks. This species is known from Patagonia, Burdwood Bank and the Falklands.

Ritchie also recorded it from ‘eight miles north of Dassen Island, Cape Colony’.

However, the South African material was not mentioned by Rees & Thursfield in

their revision of Ritchie’s collection and one must assume that it no longer exists.

Since the identification cannot be checked and since there are so many closely related

species of Symplectoscyphus, the record is best regarded as doubtful until such time

as it can be confirmed.

320 ANNALS OF THE SOUTH AFRICAN MUSEUM

S. filiformis is rather similar in appearance to S. arboriformis but has smaller

hydrothecae with a greater proportion adnate, and the gonotheca has very prominent

transverse ridges.

Symplectoscyphus indivisus (Bale, 1882)

Sertularella indivisa Bale, 1882: 24, pl. 12 (fig. 7).

Symplectoscyphus indivisus: Millard, 1961: 207. Ralph, 1961a: 803, fig. 15i-k.

Remarks. The only record of this species is two slides from Busk’s collection reputed

to come from Algoa Bay and identified by Millard (1961). It has not been discovered

since and as with several of Busk’s records needs confirmation before acceptance.

S. indivisus differs from other South African species of the genus in its annulated

hydrothecae.

Symplectoscyphus johnstoni (Gray, 1843)

?Sertularia gaudichaudi: Busk, 1851: 118.

Remarks. Busk recorded the presence of ‘Sertularia gaudichaudi’ in South Africa.

Since that time Billard (1922 and other papers) has shown. that Sertularia gaudichaudi

Lamouroux, 1824 is a Sertularella. Millard (1961) showed that Busk’s material, reput-

ably from Algoa Bay, is neither a Sertularia nor a Sertularella, but a species of Symplec-

toscyphus, possibly S. divaricatus (Busk, 1852) or S. johnstoni (Gray, 1843). Ralph

(1961a), in a revision of the New Zealand species of Symplectoscyphus, described and

figured the type material of both S. divaricatus and S. johnstoni. From this account it is

clear that Busk’s South African material is closer to the latter species. However,

since the material is badly preserved and the species has not been reported again, the

record is better dropped until such time as it can be confirmed.

Symplectoscyphus unilateralis (Lamouroux, 1824)

Sertularia unilateralis Lamouroux, 1824: 615, pl. 90 (figs 1-3). ?Busk, 1851: 118.

Sertularella unilateralis: Hartlaub, 1901a: 42, fig. 20.

Remarks. Busk attributed material from Algoa Bay to this species with a query.

Busk’s material could not be found in the British Museum and probably no longer

exists. The record should be dropped.

Genus Thuiaria Fleming, 1828

Diagnosis. Stem erect, bearing hydrothecae in two longitudinal rows and hydro-

cladia in whorls or in two longitudinal rows. Hydrocladia different in structure

to stem, with internodes of irregular length, often branched. Hydrotheca sessile,

partly or completely adnate, without distinct marginal teeth. Operculum of

one large, abcauline valve. Hydranth with abcauline caecum.

Type species: Sertularia thuja Linnaeus, 1758.

Remarks. The opinion of Billard (1925a: 137) is adopted that Thuiaria and

Salacia are separate species distinguished by the presence or absence respectively

of an abcauline caecum.

There are no species in South Africa which can be attributed to this genus

with any certainty.

Doubtful species

Thuiaria doliolum Kirchenpauer, 1884

Thuiaria doliolum Kirchenpauer, 1884: 27, pl. 13 (fig. 4).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 321

Remarks. This species is insufficiently described and has not been reported again.

Kirchenpauer gives the locality as “Cape of Good Hope’. His figures suggest Salacia

articulata, in which species the gonothecae are occasionally annulated (Ritchie 1909:

fig. 6).

Leloup (1974) refers 7. doliolum to a new genus Parathuiaria created for Sertu-

lariidae with hydrothecae in opposite pairs and without operculum, but there is no

real information as to the presence or absence of an operculum or abcauline caecum.

Genus Thyroscyphus Allman, 1877

Syn. Cnidoscyphus Splettstdsser, 1929.

Diagnosis. Stem erect, branched, bearing two rows of alternate hydrothecae.

Hydrotheca pedicellate and free from stem, large, campanulate to tubular.

Margin with four teeth which may be indistinct. Operculum pyramid-shaped,

of four valves, sometimes shed early. Diaphragm present. Hydranth without

caecum but with an annular fold. Nematocysts of at least two kinds, large and

small.

Type species: Thyroscyphus ramosus Allman, 1877.

KEY TO SPECIES

1. Hydrotheca funnel-shaped, radially symmetrical or nearly so, never concave on abcau-

line side. Smaller branches zigzag .. ; T. aequalis

— Hydrotheca tubular and bilaterally symmetrical, ‘usually concave on abcauline side.

Smaller branches not zigzag a Ai, 5 Be Me T. fruticosus

Thyroscyphus aequalis Warren, 1908

Fig. 103

Thyroscyphus aequalis Warren, 1908: 344, fig. 23, pl. 48 (figs 38-40). Millard, 1964: 52, fig.

Thyroscyphus regularis: Jaderholm, 1923a: 5. Stechow, 1925a: 463.

Cnidoscyphus aequalis: Splettst6sser, 1929: 82, 124, figs 78-82.

Diagnosis. Stem stiff and woody, fascicled near base in larger colonies, giving

off irregularly alternate branches, reaching 400 mm in height but usually much

less. Smaller branches (hydrocladia) distinctly zigzag. The two rows of branches

and hydrothecae in one plane. Stem and branches divided into internodes by

oblique nodes sloping in alternate directions, each internode bearing a hydro-

theca on an apophysis at distal end.

Hydrothecal pedicel short, about half width of apophysis, spirally grooved.

Hydrotheca large, more or less funnel-shaped and expanding to margin, but

occasionally with slight bilateral tendencies; abcauline wall never concave;

0,8-1,3 mm in height from diaphragm and 0,4-1,2 mm in marginal diameter.

Margin with four distinct equidistant teeth and thickened ridge just below edge.

Operculum fairly persistent. Diaphragm in form of thickened perisarcal ring,

more powerfully developed on adcauline side. Hydranth with about 32 tentacles.

Large nematocysts rod-shaped, present in two batteries (adcauline and

abcauline) in distal part of ectodermal lining of hydrotheca (Fig. 81C).

322 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 103.

Thyroscyphus aequalis. A, stems; B, hydrocladium; C-—F, hydrothecae; G, male gonotheca.

Scale: A in cm, B in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 323

Gonothecae borne on stem apophyses, male elongated, widening towards

distal end which is obliquely truncated, smooth or roughly corrugated, with

external marsupium, reaching 2,5 mm in length and 1,5 mm in maximum

diameter. Female unknown.

Colour: opaque yellowish-white when preserved.

Variation. The nodes of the stem are usually distinct, but sometimes only faintly

indicated. Sometimes two hydrothecae arise from the same apophysis.

The spiral grooving of the hydrothecal pedicel is variable, it may reach

a maximum development of 24 turns, usually with half a turn more on the

abcauline side, or it may be barely visible. Regeneration nodes commonly

occur in the pedicel and obscure the grooving. The shape and size of the hydro-

theca vary, from a large form with a wide mouth and practically symmetrical

sides, to a smaller form with narrower mouth and protruberant adcauline wall.

The hydrotheca often possesses an extra internal ridge of perisarc at about one-

third of its height for the attachment of the annular fold of the hydranth, but

this is only present in the older hydrothecae.

Distribution outside South Africa. Tropical East Africa, Madagascar, India.

Type locality: Algoa Bay, South Africa.

Distribution in South Africa. False Bay to Mocambique, common on the

Agulhas Bank and in Natal, littoral to 219 m. 34/18 (s), 34/20 (s), 34/21 (s),

35/21 (d), 34/24 (d), 33/25 (s), 34/25 (s), 33/26 (s), 33/27 (s), 32/28 (s), 33/28 (s),

31/29 (1), 30/30 (s), 30/31 (s, d), 29/31 (s, d), 28/32 (s, d), 25/32, 25/33 (s), 24/34

(s), 24/35 (s)

Thyroscyphus fruticosus (Esper, 1793)

Fig. 104

Spongia fruticosa Esper, 1793: 188.

me ones fruticosus: Splettstésser, 1929: 7, 122, figs 1-11, 13-27. Vervoort, 1967: 35,

gs 8-9.

Diagnosis. Stem stiff and woody, unfascicled, giving off irregularly alternate

hydrocladia in one plane, reaching 130 mm, with segmentation visible on smialler

branches only, branches not zigzag. The two rows of hydrocladia and

hydrothecae in one plane.

Hydrothecal pedicel short, borne on a wide apophysis of stem from which

it is separated by a partial or complete node, unsegmented, but normally

demarcated from hydrotheca by a shallow groove on abcauline side. Hydro-

theca tubular, not expanding to margin, curved outwards, with adcauline wall

convex and abcauline wall straight or slightly concave, 0,7—-1,1 mm in abcauline

height and 0,4-0,5 mm in marginal diameter. Margin with four low, rounded

teeth and thickened ridge just below edge. Operculum shed early. Diaphragm

in form of thickened perisarcal ring, more powerfully developed on adcauline

side.

324 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 104.

Thyroscyphus fruticosus. A, hydrocladium; B, stem; C and D, hydrothecae; E, gonotheca.

Scale: B in cm, A in mm, the rest in mm/10.

Large nematocysts bean-shaped, present in body of hydranth only

(Splettstdsser).

Gonotheca arising from stem apophysis below hydrotheca, elongate-

oval, smooth, a little larger than hydrotheca, female obliquely truncated distally,

containing one egg which develops into a planula in situ. No external marsupium.

Colour: pale rose when living, yellow when preserved.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA S20

Remarks. The female gonotheca is reported to be wider and shorter than the

male.

Distribution outside South Africa. Indo-Pacific and mainly tropical, from

the Mediterranean and east coast of Africa through India and the East Indies

to Fiji and New Zealand.

Distribution in South Africa. Inhaca, Mogambique. 26/32 (1)

Family Plumulariidae

Diagnosis. Hydrothecae borne on hydrocladia and sometimes on stem as well,

always on one surface and forming a single row. Hydrotheca sessile, and at

least partly adnate, without a true diaphragm but with a definite floor, without

operculum, bilaterally symmetrical. Hydranth with a single circle of filiform

tentacles and a conical hypostome. Nematophores always present and usually

contained in nematothecae. Gonophores in the form of fixed sporosacs.

Introduction. The Plumulariidae form a fairly well-defined family, the members

being easy to recognize. But subdivision within it is not easy, as many characters

are variable both between and within species. There are four subfamilies, which,

though easily recognized by an expert, are not easily separated in a key. These

are the Halopterinae, Kirchenpaueriinae, Plumulariinae and Aglaopheniinae.

Members of a subfamily are related by a set of characters, all of which do not

necessarily occur in every genus. Thus the key on p. 329 is for convenience only;

it does not attempt to include all possible characters. The reader should turn to

the diagnoses of the subfamilies for confirmation.

Branching is very variable and complicated by the fact that some species

can exist in more than one form. The stem may be simple and unbranched,

arising directly from the hydrorhiza and bearing hydrothecae directly (in this

case the terms ‘stem’ and HYDROCLADIUM are synonymous); or the stem may

bear one order of branches (the branches are hydrocladia); or it may bear two

or more orders (the final ones are hydrocladia) (Fig. 7).

The most characteristic type of branching is the pinnate type, with alternate

or opposite hydrocladia arising from the stem or a branch thereof. Dichotomous

branching occurs in Aglaophenia pluma and whorled branching in Nemertesia.

A few genera exhibit sympodial branching. Thus, in Monostaechas the primary

simple stem (hydrocladium) branches from the posterior surface as a helicoid

sympodium, but in M. quadridens branching starts as a dichotomous sympodium

and changes more distally to a helicoid sympodium. In Thecocarpus flexuosus

the main stem gives rise to a number of scorpioid sympodia, each of which is

twisted into a spiral and bears hydrocladia.

Hydrocladia are usually simple, but may also branch. If this branching

occurs regularly it may be used as a diagnostic character, as in Monostaechas

and Schizotricha (sympodial branching) and in Oswaldella (dichotomous

branching)

326 ANNALS OF HE SOUTH AFRICAN MUSEUM

The stem may be fascicled or unfascicled. Two types of FASCICULATION

occur. In the first and most common, the stem has a single axial tube, which

alone bears the hydrocladia and is surrounded to a greater or lesser extent by

peripheral tubes. Branches may arise from the axial tube (e.g. Cladocarpus

lignosus) or from the peripheral tubes (e.g. Nemertesia ciliata).

Ay ae

\ aa

A B

Fig. 105.

Plumulariidae: fascicled stems and branching. A, branching from the axial tube as in Clado-

carpus; B, branching from a peripheral tube as in Nemertesia; C, branching by separation

of similar tubes as in Corhiza.

The second type of fasciculation occurs in Corhiza, where the stem has no

special axial tube, but consists of a bundle of similar tubes, any one of which

may diverge to form a hydrocladium. Branching here is simply a separation of

groups of tubes.

Some species may exist in two growth-forms, though usually one or the

other is dominant. Thus, in Antennella secundaria the simple stem is normal,

but opposite pinnate branching of the first order may occur. In Halopteris

pseudoconstricta, Plumularia filicaulis and Gattya humilis alternate pinnate

branching of the first order is normal, though simple stems may also occur.

A number of branching species are known to have epizootic forms in which

the growth is stunted and seldom develops further than the simple stage (e.g.

Gymnangium arcuatum, G. exsertum and G. africanum). These forms when first

described were placed in separate varieties or subspecies. It is now recognized

that they are growth-forms only. Sometimes such stunted forms occur on the

normal form of the same species (AUTO-EPIZOOTIC). Oswaldella nova, so far

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 327

known only as an epizooite, is possibly such a stunted form, of which the normal

form remains to be discovered.

In most branching genera the hydrothecae are confined to the hydrocladia,

so that the stem internodes are athecate and differ from those of the hydrocladia.

But in Halopteris, Gattya and Schizotricha both the stem and the hydrocladia

bear hydrothecae. Cauline hydrothecae occur only in the Halopterinae and form

a useful diagnostic character.

A hydrocladium may bear hydrothecae on every internode (HOMOMEROUS),

or on every alternate one (HETEROMEROUS). The condition may vary in a single

colony, when the hydrocladia tend to be homomerous proximally and hetero-

merous distally due to the cutting off of short athecate internodes from the longer

thecate ones.

HINGE-JOINTS, in the form of very pronounced oblique nodes, may occur

in various parts of the colony, usually near the base of the stem, its branches or

the hydrocladia.

The hydrothecae are always bilaterally symmetrical and sessile, with the

adcauline wall partly or completely adnate to the hydrocladium. No true

diaphragm is present, but there is a definite floor to the hydrotheca perforated

by a hydropore of varying size. An intrathecal septum may be present, either

adcauline or abcauline in position, e.g. Lytocarpus and Pycnotheca.

The hydrothecal margin may be toothed (as in Gattya, Dentitheca and most

Aglaopheniinae) or untoothed. Sometimes the median abcauline tooth is

produced into a long hollow or solid spine (e.g. Thecocarpus), and sometimes

the perisarc along the abcauline wall of the hydrotheca is thickened and forms a

Keel-like ridge, which may also be produced as a spine.

Nematophores are always present, and usually they are contained in

NEMATOTHECAE. The latter are best developed in the Plumulariinae, where they

are typically movable and two-chambered, with a slender basal chamber and a

funnel-shaped distal chamber. However, the structure varies and they may be

fixed and one-chambered (some species of Halopteris) or reduced to small saucer-

shaped or scoop-shaped structures (Kirchenpaueria). The final stage in reduction

occurs in some species of Kirchenpaueria, where the nematotheca is completely

absent and the nematophore (usually termed a naked SARCOSTYLE) emerges

through a hole in the perisarc (Fig. 8).

The basic arrangement of nematothecae includes one median inferior

below each hydrotheca and one lateral on each side. In addition to, or instead

of, the latter, one or more superior nematothecae may be seated above the

level of the hydrotheca. Many variations of this pattern occur, and extra lateral

or superior nematothecae may be present.

In the Aglaopheniinae the basic three nematothecae are rigidly present;

they are always one-chambered and immovable, but often develop other com-

plexities. The laterals are fused to the side-wall of the hydrotheca and some-

times have more than one opening. The median inferior may be fused to the

abcauline face of the hydrotheca and may have an opening into it. Its distal

328 ANNALS OF THE SOUTH AFRICAN MUSEUM

2nd median Superior

1st median Superior

1st lateral

9nd lateral

- pedicel

median inferior

FRONT VIEW

SIDE VIEW

mamelon

stem

hydrocladium

cauline nematothecae

apophysis

ORIGIN OF HYDROCLADIUM

Fig. 106.

Plumulariidae: position of nematothecae.

opening may be duplicated and its distal end may be drawn out into a long tube

reaching well beyond the hydrothecal margin.

In most of the Halopterinae the laterals (or the first pair of laterals if two

are present) are seated on long pedicels fused to the side-walls of the hydrotheca.

In addition to those associated with the hydrothecae, nematothecae may

occur on athecate stems or internodes, on the peripheral tubes of fascicled

stems, on the hydrorhiza and on the gonothecae or other reproductive bodies.

Nematothecae may provide useful characters for specific diagnosis, but

it must be borne in mind that they are easily lost in dredged and preserved

material.

A structure of doubtful function, the MAMELON, is characteristic of many

Plumulariinae. It is a small nipple-like protuberance bearing a terminal opening

and is seated on the upper surface of the hydrocladia-bearing apophysis of the

stem. Its aperture communicates with the cavity between the perisarc and

coenosarc. It possibly contains a nematophore in life, or it may be concerned

with the hydrostatic pressures of the colony. In the few cases of hydroids para-

sitic on Plumulartidae (e.g. Hebella furax) the parasitic hydrorhiza appears to

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 329

gain entry through the mamelon. In the Aglaopheniinae the mamelon is well

developed and more like a reduced nematotheca in appearance.

Gonophores are always in the form of fixed sporosacs contained in gono-

thecae. Many species are dioecious and in most the gonothecae are sexually

dimorphic. In the Plumulariinae, Kirchenpaueriinae, Halopterinae and the

genus Gymnangium among the Aglaopheniinae the gonothecae are borne singly

on the stem, hydrocladia or hydrorhiza, but in other Aglaopheniinae protective

branchlets or PHYLACTOCARPS are present (Fig. 9). These may be formed as

appendages to a hydrocladium, as in Cladocarpus, or may represent modified

hydrocladia as in Lytocarpus. In the latter, hydrocladia are transformed into

phylactocarps at maturity. In L. phoeniceus, for example, every third hydro-

cladium ruptures above the level of the first hydrotheca and regenerates as a

phylactocarp. In Thecocarpus and Aglaophenia the phylactocarp, a modified

hydrocladium, forms a pod-shaped structure, the CORBULA. This consists of a

central axis and a number of lateral ribs provided with nematothecae and

arching over to enclose the gonothecae. The corbula may be open, when the

ribs remain separate, or closed, when the ribs fuse with one another. Among

the Aglaopheniinae genera are separated largely on the reproductive structures.

KEY TO SUBFAMILIES

1. Paired lateral nematothecae present and fused to hydrotheca AGLAOPHENIINAE Pp. 407

— Paired lateral nematothecae present or absent, when present not fused to hydrotheca 2

2. Paired lateral nematothecae absent. Median nematothecae usually reduced and

seldom two-chambered Bs 3 oe Bes ae KIRCHENPAUERIINAE p. 370

— Paired lateral nematothecae present. Nematothecae usually two-chambered, seldom

reduced ke i: a a By; “ mM: or -: se 3

3. Hydrocladia arising from erect stem. No cauline hydrothecae. Stem, when fascicled,

giving rise to hydrocladia from a single axial tube 578 .. PLUMULARIINAE p. 379

— Hydrocladia arising independently from the hydrorhiza or from erect stem. Stem or

branches either with cauline hydrothecae or fascicled and giving rise to hydrocladia

or pinnae from any of its component tubes on Be a HALOPTERINAE p. 329

Subfamily Halopterinae

Diagnosis. Erect stem present or absent. Hydrocladia originating (a) inde-

pendently from hydrorhiza, or (6) from a pinnate stem possessing cauline

hydrothecae, or (c) irregularly from the superficial tubes of a fascicled stem or

its branches. Branches when present bearing cauline hydrothecae. Hydrocladia

branched or unbranched. Hydrothecae generally large (over 0,2 mm in depth),

with toothed or untoothed margin. Nematothecae of variable structure, one-

or two-chambered, movable or immovable, but never fused to hydrothecae,

at least three associated with every hydrotheca, o1.e median inferior, and one

pair laterals; the laterals generally borne on pedicels which are adherent to the

hydrotheca. Gonothecae unprotected, not aggregated, usually dimorphic and

with the female bearing nematothecae.

330 ANNALS OF THE SOUTH AFRICAN MUSEUM

KEY TO GENERA

No erect stem; hydrocladia arising separately from hydrorhiza 2

Erect stem present, giving rise to hydrocladia either directly or from ‘branches: but

sometimes with a simple growth-form when hydrocladia arise separately from hydro-

rhiza (for these see key to Antennella below) ae af oe oe = Bit)

Hydrocladia unbranched .. ae 48 ee ate .. Antennella p. 330

Hydrocladia branching sumacaiky ae Re - os Monostaechas p. 362

Hydrotheca with toothed margin .. % ae as * a Gattya p. 341

Hydrotheca with untoothed margin es ao ee Sct PE5e oe riers

Hydrocladia branched ahs R: ~ is re ae: ae ae ATS

Hydrocladia unbranched .. oe 3 - ss se a - pc)

Hydrocladia branching sympodially from posterior surface (opposite side to hydro-

theca) . : Monostaechas p. 362

Hydrocladia Searenns Som anterior or ‘Jateral surface immediately below hydro-

thecae .. oP et - ne a a it Me Schizotricha p. 368

Stem fascicled and composed of tubes of equal importance, any of which may give

rise to hydrocladia or branches which are actuate arranged. Cauline hydrothecae

present on branches, not on stem et Corhiza p. 334

Stem fascicled or unfascicled; if fascicled with an j axil tube which alone bears hydro-

cladia. Hydrocladia pinnately arranged. Cauline hydrothecae present .. Halopteris p. 349

Genus Antennella Allman, 1877

Syn. Antennellopsis Jaderholm, 1896.

Diagnosis. No true stem present. Hydrecladia arising independently from

hydrorhiza, normally unbranched, unfascicled. Hydrotheca cup-shaped, with

untoothed margin.

Type species: Antennella gracilis Allman, 1877

—

KEY TO SPECIES OF ANTENNELLA AND SIMPLE FORMS OF BRANCHING GENERA

[Species not represented in South Africa are bracketed]

Hydrotheca with toothed margin .. as fi nF oe Gattya humilis

Hydrotheca with untoothed margin aE See ne i sie Reyes 72

Two pairs of lateral nematothecae . . ne a ve a Sic 53 5 eS

One pair of lateral nematothecae .. ane oe ® 3 - ae a og)

Larger pair of lateral nematothecae with wineglass-shaped distal chamber, which

has a deep emargination on adcauline wall Corhiza pannosa

Larger pair of lateral nematothecae with funnel- shaped distal chamber Se taal

No athecate internodes. Hydrotheca adnate for about 3 height. At least one superior

nematotheca present above hydrotheca .. .. Monostaechas natalensis

Intermediate athecate internodes present. Eiydrottices adnate for about 4 height. No

superior nematothecae - *F - ee - % 4 na. x eae)

Athecate intermediate internodes normally bearing one nematotheca Antennella africana

Athecate intermediate internodes normally bearing two or three nematothecae

[Antennella quadriaurita]

- Hydrocladia branching sympodially from posterior surface, the main axis formed

by the bases of successive hydrocladia .. Monostaechas quadridens

Hydrocladia normally unbranched; if branched the main axis formed by the primary

hydrocladium by:

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 331

7. Hydrotheca with free part of adcauline wall more or less straight. A one-chambered

superior nematotheca present in angle behind adcauline wall of hydrotheca

Antennella secundaria

— Hydrotheca with free part of adcauline wall distinctly hollow. No superior nemato-

thecae: .. A ate ate ee es ele od Halopteris pseudoconstricta

Antennella africana Broch, 1914

Fig. 1O7A-E

Antenella quadriaurita forma africana Broch, 1914: 26.

Antenella africana: Stechow, 1925a: 492, fig. 41.

Antennella serrata Totton, 1930: 212, fig. 53.

Antennella africana: Millard, 1957: 226. Ralph, 19616: 23, fig. la—c, f—g, k.

Diagnosis. Hydrocladia arising separately or in clusters from entwined hydro-

rhiza, often epizootic on other hydroids and found on the spider-crab, Macro-

podia falcifera (Stimpson). Hydrocladia reaching 31 mm in height, consisting

of a short basal athecate part with a variable number of transverse nodes and a

longer distal part with alternate thecate internodes terminated by transverse

nodes and athecate internodes terminated by more distinct steeply oblique nodes.

Athecate intermediate internodes normally with one median nematotheca.

Thecate internodes with five nematothecae, one median inferior and two pairs

laterals, one large and one small.

Hydrotheca cup-shaped, with more or less parallel sides, adnate for about

half adcauline length, 0,19-0,3 mm in abcauline height and 0,2-0,3 mm in

marginal diameter. Margin forming an angle of 50-60° with internode.

Median inferior nematotheca seated well below hydrotheca and not reach-

ing its base, movable, two-chambered; distal chamber scoop-shaped with low

adcauline wall. The larger lateral nematotheca seated on a finger-shaped pedicel

arising below top of adnate part of hydrotheca, not reaching thecal margin,

movable, two-chambered ; distal chamber funnel-shaped, with wall emarginated

on two sides resulting in a bivalved appearance with a large lateral valve and

a small median valve. The smaller lateral nematotheca seated in axil of pedicel

of larger one, of approximately the same length as pedicel, of the same structure

as larger one.

Gonothecae borne immediately below hydrothecae, singly or in pairs,

male and female either on separate hydrocladia, or on the same one with the

male more distal than the female. Female gonotheca large, pear-shaped, with

wide operculate distal aperture, bearing two large, two-chambered nemato-

thecae on basal region, with a pedicel of two segments. Male gonotheca smaller,

spindle-shaped and curved, with small distal aperture, bearing one large, two-

chambered nematotheca on basal region, with a pedicel of one segment.

Variation. The intermediate athecate internodes are of variable length and may

be longer than the thecate ones (usually the case in the proximal region) or

shorter (usually the case in the distal region). The number of nematothecae

on the intermediate athecate internodes is usually one in this species, though

sometimes two and rarely three. In the closely related Antennella quadriaurita

S32) ANNALS OF THE SOUTH AFRICAN MUSEUM

Ritchie from the Atlantic the number is usually two or three and rarely four.

It is possible that these two species should be combined.

Distribution outside South Africa. Tropical West Africa and New Zealand.

Type material from Setté Cama, Congo, and from Luderitz Bay, South West

Africa.

Distribution in South Africa. Abundant round the west and south coasts from

Liideritz Bay to Natal, littoral to 450 m. 26/15 (s), 32/18 (s), 33/17 (s), 33/18

(1, s), 34/18 (1, s), 34/20 (s), 34/21 (s), 34/22 (s), 34/23 (s, d), 34/24 (d), 33/25 (s),

34/25 (Ss, d), 33/26 (s,-d); 33/27 (Ss), 32/28 (Ss), 32/29 @); 28/32 @) 2732@

Antennella secundaria (Gmelin, 1791)

Fig. 107F—L

Sertularia secundaria Gmelin, 1791: 3854.

Antennella natalensis Warren, 1908: 318, fig. 14.

Antennella secundaria: Millard, 1958: 199. Millard, 1962: 274. Vervoort, 1967: 42, fig. 12.

Diagnosis. Hydrocladia reaching 12 mm in height, consisting of a short basal

athecate part with a variable number of transverse nodes and a longer distal

part with alternate thecate internodes terminated by transverse nodes (often

indistinct) and athecate internodes terminated by steeply oblique nodes, the

first oblique node forming a hinge-joint. Athecate intermediate internodes with

one or two median nematothecae. Thecate internodes with four nematothecae,

one median inferior, one pair laterals and one median superior.

Hydrotheca cup-shaped, with more or less parallel sides, adnate for about

half adcauline length, 0,15—0,2 mm in abcauline height and 0,15-0,3 mm in

marginal diameter. Margin forming an angle of 35—50° with internode.

Median inferior nematotheca seated below hydrotheca and not, or only

just, reaching its base, probably movable, two-chambered; distal chamber

scoop-shaped with reduced adcauline wall. Lateral nematotheca seated on

a finger-shaped pedicel arising on a level with top of adnate part of hydrotheca,

usually not reaching thecal margin, movable, two-chambered; distal chamber

funnel-shaped with low wall on medial side, somewhat variable in structure.

Median superior nematotheca seated behind free adcauline part of thecal wall

and not reaching margin, minute, one- or indistinctly two-chambered.

Gonothecae borne immediately below hydrothecae, singly or in pairs,

curved, pear-shaped, bearing two large, two-chambered nematothecae on

basal region, with a pedicel of two segments, male and female on the same

hydrocladium, with the male more proximal than the female. Female gonotheca

large, with a wide operculate distal aperture. Male gonotheca smaller, rounded

distally.

Variation. Antennella secundaria can on occasion produce upright pinnate

colonies similar to Halopteris, in which the internodes of the stem are similar

to those of the hydrocladia. The hydrocladia are given off alternately, except

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 333

Fig. 107.

Antennella africana. A, hydrocladium with male gonothecae; B, female gonotheca;

C-E, lateral nematothecae.

Antennella secundaria. F and G, hydrocladia, F with a proximal male and a distal female

gonotheca; H-L, lateral nematothecae.

Scale in mm/10.

334 ANNALS OF THE SOUTH AFRICAN MUSEUM

for the first two which are opposite. It can also produce branches from the

posterior surface of the hydrocladium as does Monostaechas. Only the latter

type has been seen in South Africa; there are never more than two branches to

a hydrocladium, and these arise from the basal athecate region. The main axis

is formed by the first hydrocladium and not by the bases of successive hydro-

cladia as in Monostaechas. The length of the athecate internodes is variable and

may or may not exceed that of the thecate internodes in length.

A form with extra long nematothecae (about double the height of the

hydrotheca) and shallow hydrothecae (0,11 mm abcauline height) also occurs.

Distribution. Cosmopolitan. Type locality: Mediterranean Sea.

Distribution in South Africa. Cape Agulhas on the south coast to Mocambique,

littoral to 164 m. Not common in any one locality. 35/19 (s), 35/20 (d), 34/22

(s), 34/24 (d), 33/25 (s), 34/25 (s), 33/26 (s), 33/27 (s), 32/28 (s), 33/28 (s), 30/30

(1, s), 30/31 (d), 29/31 (s), 28/32 (s), 26/32 (1, s), 24/34 (s), 24/35 (s), 21/35

Genus Corhiza Millard, 1962

Diagnosis. An erect fascicled stem present, which may be branched or

unbranched, and is composed of intercommunicating tubes of equal diameter

and importance, these tubes giving rise irregularly to hydrocladia or to branches

which bear hydrocladia. Branches, if present, bearing cauline hydrothecae

and pinnately arranged hydrocladia. Hydrocladia unbranched, occasionally

(as a secondary growth-form) arising independently from hydrorhiza. Hydro-

theca cup-shaped, with untoothed, though sometimes sinuated, margin.

Type species: Antennopsis scotiae Ritchie, 1907.

KEY TO SPECIES

1. Only one pair of lateral nematothecae .. ee ai me te x 4: Pg

— More than one pair of lateral nematothecae sa 3

2. Stem and branches giving rise directly to fdiocindine Lateral neniatotheese not

reaching thecal margin : C. mortenseni

— Stem and branches giving rise to ‘sub- branches which bear hydrocladia. Lateral

nematothecae overreaching thecal margin se : is C. valdiviae

3. Stem branching in lower region only. Branches very lone ace nematothecae

with funnel-shaped distal chamber which is not emarginated .. Be .« _Gescotiag

Branching irregular, colony short and bushy = ‘ bos De ie!

4. Two pairs of lateral nematothecae, with wineglass- shaped distal ohianitier which is

emarginated on mesial wall. One nematotheca below base of hydrotheca C. pannosa

~ More than two pairs lateral nematothecae, with distal chamber cut away on two sides,

giving a bivalve appearance. Three nematothecae below base of hydrotheca_ C-. bellicosa

Corhiza bellicosa Millard, 1962

Fig. 108A—D

Corhiza bellicosa Millard, 1962: 275, fig. 2A—-E.

Diagnosis. Colony branching irregularly, reaching a maximum height of 50 mm.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 335

Component tubes of stem and branches diverging from one another to form

hydrocladia in an irregular fashion.

Hydrocladium with a proximal region consisting of a variable number of

athecate internodes bearing a double series of nematothecae and terminated by

transverse nodes, except for the last which is terminated by an oblique node,

then thecate internodes only, separated by oblique nodes. Each thecate inter-

node bearing one hydrotheca and 11-18 nematothecae, one median inferior,

four pairs laterals and two to nine superior.

Hydrotheca deep-campanulate, almost completely adnate, deeper than

wide, with no intrathecal septum, 0,2—0,3 mm in height (in centre) and 0,16-

0,2 mm in marginal diameter. Margin even, at right angles to internode.

Nematothecae all large, two-chambered and movable; distal chamber

emarginated on two sides forming a bivalve structure with a large abcauline

valve and a smaller adcauline valve. Median inferior nematotheca seated well

below hydrotheca and not reaching its base. Lateral nematothecae: first pair

seated below hydrotheca at a slightly higher level than median inferior and just

reaching base of hydrotheca; second pair borne on finger-shaped pedicels at

sides of hydrotheca and not quite reaching thecal margin; third pair borne in

the axils of the pedicels of the second pair; fourth pair borne at the sides of the

hydrotheca between the pedicels of the second pair and the thecal margin,

overtopping thecal margin. Superior nematothecae most commonly including

two pairs, one pair seated behind free part of thecal wall and overtopping its

margin, and the other at a higher level and more laterally placed, but number

and arrangement very variable.

Gonothecae unknown.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 33°3’S/

2h). 27 mi.

Distribution in South Africa. Agulhas Bank, between Port Elizabeth and East

London, 27-84 m, rare. 34/25 (s), 33/27 (s)

Corhiza mortenseni Millard, 1968

Fig. 108E-H

Corhiza mortenseni Millard, 1968: 274, fig. 5A—D.

Diagnosis. Colony branching in a subdichotomous manner, reaching a maximum

height of 47 mm. Component tubes of stem and branches giving rise to hydro-

cladia irregularly and on all sides. Hydrocladia forming almost a right angle

with stem.

Hydrocladium bearing hydrothecae on upper surface, consisting of up to

two long athecate and anematothecate internodes terminated by straight nodes,

one long athecate internode bearing two to four median nematothecae and

terminated by a steeply oblique node, then alternate short thecate and longer

athecate internodes terminated by straight and steeply oblique nodes respectively.

336 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 108.

Corhiza bellicosa. A and B, hydrocladia in lateral and anterior view respectively; C, stems;

D, lateral nematothecae.

Corhiza mortenseni. E, stem; F, part of fascicled stem showing origins of hydrocladia;

G and H, hydrothecae.

Scale: C and E in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 337

Each thecate internode bearing one hydrotheca and four nematothecae, one

median inferior, one pair laterals and one median superior. Each intermediate

athecate internode bearing two median nematothecae.

Hydrotheca cup-shaped, with parallel walls flaring slightly at margin,

adnate for about half adcauline height, with no intrathecal septum, 0,14—-0,2 mm

in abcauline height and 0,19-0,2 mm in marginal diameter. Margin even, forming

an angle of 20—40° with internode.

Nematothecae all two-chambered and movable; distal chamber funnel-

shaped, with adcauline wall lower than abcauline. Median inferior nematotheca

not reaching base of hydrotheca. Lateral nematotheca borne on finger-shaped

pedicel at side of hydrotheca and not quite reaching thecal margin. Median

superior nematotheca borne behind free part of adcauline thecal wall and not

reaching thecal margin.

Gonothecae unknown.

Distribution. Endemic to South Africa. Type locality: off Natal, 29°48,5’S/

31°18’E, 219 m.

Distribution in South Africa. East London to Natal, 88-219 m, rare. 33/27 (s),

30/31 (d), 29/31 (d)

Corhiza pannosa Millard, 1962

Fig. 109F-K

Corhiza pannosa Millard, 1962: 278, fig. 3A—B, D-G.

Diagnosis. Colony capable of producing two growth-forms, one in which

hydrocladia arise from an erect stem, and one in which hydrocladia arise

independently from the hydrorhiza, the latter often epizootic on other hydroids.

Stem branching irregularly, reaching a maximum height of 53 mm, its component

tubes giving rise to hydrocladia in an irregular fashion.

Hydrocladium consisting of two or more athecate internodes bearing a

double series of nematothecae and terminated by transverse nodes except for the

last which is terminated by an oblique node, then normally thecate internodes

terminated by oblique nodes. Each thecate internode bearing one hydrotheca

and six to eight nematothecae, one median inferior, two pairs laterals and one

to three median superior. In some regions the distal part of the thecate inter-

node cut off by a transverse node taking with it the superior nematothecae.

Hydrotheca cup-shaped, with almost parallel sides, adnate for about half

height, with no intrathecal septum, 0,3—0,5 mm in abcauline height and 0,3—

0,4 mm in marginal diameter. Margin even, forming an angle of about 50°

with internode.

Nematothecae all two-chambered and movable. Median inferior nemato-

theca seated below hydrotheca and not reaching its base; distal chamber

scoop-shaped with very low adcauline wall. First pair lateral nematothecae

seated on finger-shaped pedicels at sides of hydrotheca and not reaching thecal

338 ANNALS OF THE SOUTH AFRICAN MUSEUM

margin; distal chamber wineglass-shaped and deeply emarginated on mesial side.

Second pair lateral nematothecae seated in axils of pedicels of first pair; distal

chamber wineglass-shaped, with mesial wall lower than lateral wall.

Gonothecae borne on the hydrocladia below the hydrothecae, singly or

in pairs, male and female on the same colony, the male more distal than the

female. Female gonotheca (described as male by Millard 1962) curved pear-

shaped, with a broad distal and operculate aperture, bearing two large nemato-

thecae near base; pedicel of one segment. Male gonotheca spindle-shaped,

smaller than female, with bluntly pointed distal end; pedicel of one segment.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 34°15’S/

23" 8 dle ane

Distribution in South Africa. From Dassen Island to East London, 11-120 m.

33/18 (s), 34/18 (s), 34/23 (s), 34/24 (d), 34/25 (s), 32/28 (s)

Corhiza scotiae (Ritchie, 1907)

Fig. 109A-E

Antennopsis scotiae Ritchie, 19076: 543, pl. 3 (fig. 3). Ritchie, 1909: 90, fig. 8.

Corhiza scotiae: Millard, 1962: 281, fig. 3C.

Diagnosis. Colony consisting of clusters of very long stems usually branching

irregularly near the base, reaching a maximum height of 330 mm. Stem and

branches thick and fascicled, the superficial tubes giving rise to hydrocladia

irregularly and on all sides. Hydrocladia close-set and forming an acute angle

with the stem.

Hydrocladium bearing hydrothecae on upper surface, consisting of two

to six athecate internodes of variable length and bearing a variable number of

nematothecae, these internodes terminated by straight nodes except for the

last which is terminated by a steeply oblique node; then alternate thecate and

athecate internodes terminated by straight and steeply oblique nodes respec-

tively. No internodal septa. Each thecate internode with one hydrotheca and

five nematothecae, one median inferior and two pairs laterals. Each intermediate

athecate internode normally with one median nematotheca.

Hydrotheca cup-shaped, with parallel walls flaring slightly at margin,

adnate for about half adcauline height, with no intrathecal septum, 0,16—-0,25

mm in abcauline height and 0,17-0,25 mm in marginal diameter. Margin even,

forming an angle of 40-60° with internode.

Nematothecae two-chambered, movable; distal chamber funnel-shaped,

not emarginated but with slightly lower adcauline wall. Median inferior nemato-

theca not reaching base of hydrotheca. One pair lateral nematothecae borne on

finger-shaped pedicels at sides of hydrotheca and not quite reaching thecal

margin; the second pair smaller and seated in the axils of the pedicels of the

first pair. Nematothecae also abundant on tubes of larger stems.

Gonothecae borne on hydrocladia below hydrothecae, male and female on

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 339

—

KES

SO Ss

—7

/ ed

ESS

ile

=>,

pyr!

= WEP” _pEciaieaase sania =

XID) IE lak is

Fig. 109.

Corhiza scotiae. A, hydrocladium with male gonothecae; B, the two lateral nematothecae

in medial (adcauline) view; C, part of fascicled stem showing origins of hydrocladia;

D, hydrocladium with female gonothecae; E, colony.

Corhiza pannosa. F, hydrocladium; G, colony; H, hydrocladium with female gonotheca;

J, the two lateral nematothecae in medial (adcauline) view; K, hydrocladium with

male gonotheca.

Scale: E and G in cm, the rest in mm/10.

340 ANNALS OF THE SOUTH AFRICAN MUSEUM

separate colonies. Female gonotheca compressed, ovate in broad view, with

truncated, operculate distal end, bearing two large nematothecae near base;

pedicel of one segment. Male gonotheca smaller, not compressed, elongate,

slightly curved, with bluntly pointed distal end; pedicel of one segment.

Variation. The intermediate athecate internodes of the hydrocladia are usually

very short and overlapped, sometimes completely, by the free part of the pre-

ceding hydrotheca, but rarely they are longer than the thecate internodes and

may then bear two median nematothecae instead of one.

In young colonies solitary hydrocladia may occur, arising directly from the

hydrorhiza.

Distribution. Endemic to South Africa. Type locality: entrance to Saldanha

Bay, 46 m.

Distribution in South Africa. From Saldanha Bay dn the west coast to East

London on the south coast, particularly common in False Bay, 18-120 m.

33/17 (s), 33/18 (s), 34/18 (s), 34/20 (s), 35/21 (d), 34/22 (s), 35/22 (d), 34/23

(s, d), 34/24 (d), 33/25 (s), 34/25 (s), 33/26 (s, d), 33/27 (s)

Corhiza valdiviae (Stechow, 1923)

Fig. 110

Heteroplon valdiviae Stechow, 1923a: 15.

Thecocaulus(?) valdiviae: Stechow, 1925a: 495, figs 42-43.

Halopteris valdiviae: Millard, 1957: 228, fig. 14B. Millard, 1962: 290, fig. 4H—J.

Diagnosis. Colony branching irregularly, reaching 370 mm. Stem and branches

stiff, thick and fascicled throughout and reaching 10 mm in diameter at base,

the component tubes diverging irregularly and on all sides to form hydrocladia-

bearing sub-branches (pinnae), without hydrothecae or nematothecae.

Sub-branches (pinnae) unfascicled or lightly fascicled; consisting of a short

basal part and a long distal thecate and hydrocladia-bearing part, the two

separated by an oblique hinge-joint; a second hinge-joint present after the first

hydrotheca. Basal part with a variable number of transverse nodes and nemato-

thecae. Distal part usually divided by oblique nodes into thecate internodes,

each bearing one hydrotheca on anterior face. An opposite pair of hydrocladia

arising by short apophyses at the sides of the first hydrotheca (i.e. between the

hinge-joints) and sometimes the second hydrotheca; remaining hydrocladia

alternate, one to each hydrotheca. Each internode with five nematothecae, one

median inferior, one pair laterals and one pair minute superior behind

hydrotheca; one or more extra nematothecae between hinge-joints.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

very short athecate and anematothecate internode terminated by a slightly

oblique node, one longer athecate internode bearing one median nematotheca

and terminated by an oblique node, then up to nine thecate internodes termi-

nated by oblique nodes. Towards tips of hydrocladia distal ends of internodes

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 341

sometimes cut off by transverse nodes to form intermediate athecate internodes.

No internodal septa. Each thecate internode with four nematothecae, one median

inferior, one pair laterals and one median superior.

Hydrotheca cup-shaped, deep, with depth normally greater than diameter,

with straight walls, adnate for about ¢ height, with no intrathecal septum,

0,17-0,2 mm in abcauline height and 0,14—0,2 mm in marginal diameter. Margin

sinuated, with high lateral walls and low adcauline wall, forming an angle of

about 60° with internode.

Median inferior nematotheca well below hydrotheca and not reaching its

base, two-chambered, possibly slightly movable; distal chamber scoop-shaped

with low adcauline wall. Lateral nematotheca borne on a triangular pedicel,

large, reaching well above thecal margin, two-chambered, movable; distal

chamber funnel-shaped, not emarginated. Superior nematotheca seated behind

free part of adcauline thecal wall and just reaching margin, minute, one-

chambered, immovable.

Male and female gonothecae borne on same colony, the female on the

sub-branches (pinnae) and the male on the hydrocladia, arising immediately

below hydrothecae, with a pedicel of one segment. Female gonotheca large,

flattened anterior-posteriorly, round to oval in front view with truncated distal

end; with three to four large nematothecae on basal part. Male gonotheca

elongate-pear-shaped, curved; with two large nematothecae on basal part.

Variation. The number of hinge-joints on the sub-branches may occasionally

be as many as four, and the hydrocladia arising between them are always in

opposite pairs. Beyond this level the normal oblique nodes may be indistinct at

first, becoming more distinct in the distal regions. The paired hydrocladia on the

first segments of the sub-branch may have three athecate internodes instead of

two at the base, of which the second and third both bear a median nematotheca.

Remarks. Due to the characteristic stem, it is necessary to transfer this species

from Halopteris to Corhiza. The appearance of the colony is very similar to

C. scotiae, differing from it in the fact that the diverging tubes of the stem form

sub-branches instead of hydrocladia.

Distribution. Endemic to South Africa. Type locality: Plettenberg Bay, 100 m.

Distribution in South Africa. Sparsely distributed round the west and south coasts

of the Cape Province, with one record from Mocambique, 4-201 m. 30/15 (d),

34/18 (s), 34/22 (s), 34/23 (s, d), 33/25 (s), 33/26 (s), 32/28 (s), 24/35 (d)

Genus Gattya Allman, 1886

Syn Paragattya Warren, 1908.

Diagnosis. An erect stem present, which may be branched or unbranched,

fascicled or unfascicled; if fascicled, with one main axial tube which bears

hydrocladia or branches. Hydrocladia pinnately arranged and borne on stem or

its branches, or (as a secondary growth-form) independently on hydrorhiza.

ANNALS OF THE SOUTH AFRICAN MUSEUM

342

Figs 110:

op O

S's

(o)

repos

(72) a“

= fey

(ae)

Shes

mae

=f)

(40)

o§

= Lal

arn

Cc —

1@)

ze:

Osd

1-5

{a0}

OO Ge

oOo

te:

ae (ea)

eae

1 8

EV)

fee

S ¢

jess

Sen

ea)

gonotheca.

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 343

Hydrocladia-bearing stem or branch with cauline hydrothecae. Hydrocladia

normally unbranched. Hydrotheca cup-shaped, with toothed margin.

Type species: Gattya humilis Allman, 1886.

KEY TO SOUTH AFRICAN SPECIES

1. Hydrocladia confined to branches (pinnae), which arise from a long, lightly fascicled

stem. Hydrotheca with straight abcauline wall .. mie .. G. heurteli

— Hydrocladia borne directly on short, unfascicled and unbranched stem, or arising

independently from hydrorhiza. Abcauline wall of hydrotheca not straight .. en 74

2. Hydrotheca with four distinct marginal teeth, one adcauline, one abcauline and

two lateral .. .. G. humilis

— Hydrotheca with two distinct marginal teeth, one adcauline and one abcauline, lateral

edges sinuated - 3

3. Abcauline marginal tooth of hydrotheca acuieed iieands Stem ‘uid iyiaroelania

usually heteromerous .. G. multithecata

— Abcauline marginal tooth of hydrotheca more or - less straight, iste and hydrocladia

usually homomerous be oe x a es oe ms G. conspecta

Gattya conspecta (Billard, 1907)

Fig. 111A-C

Plumularia conspecta Billard, 19076: 81, fig. 3. Billard, 1907a: 362, fig. 11.

Diagnosis. Stem unfascicled, unbranched, reaching 11 mm in height, consisting

of a short basal part and a long distal hydrocladia-bearing part, the two

separated by an oblique hinge-joint. Basal part with a few transverse nodes and

nematothecae. Distal part divided into thecate internodes by oblique nodes.

The first internode longer and broader than the rest, terminated by a more

distinct node and bearing one pair of opposite hydrocladia; the second inter-

node also bearing a pair of opposite hydrocladia; remaining internodes bearing

alternate hydrocladia, one to each. Each internode with one cauline hydrotheca

and six to eight nematothecae, one median inferior, one pair laterals, one median

superior and one or two pairs superior. Hydrocladial apophysis arising from

process supporting lateral nematotheca. The two rows of hydrocladia not in

one plane but set on the anterior surface of the stem.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

short athecate and anematothecate internode terminated by a straight node,

one short athecate internode bearing one median nematotheca and terminated

by an oblique node, then up to six long thecate internodes terminated by oblique

nodes. Thecate internodes without septa, with four to six nematothecae, one

median inferior, one pair laterals, one median superior and usually one pair

superior.

Hydrotheca cup-shaped and indented in middle of abcauline wall which

is markedly thickened, expanding to margin, adnate for a little over half

adcauline length, with no intrathecal septum, 0,16-0,20 mm in abcauline depth

and 0,19-0,2 mm in marginal diameter. Margin forming an angle of about 40°

with internode, with one strong abcauline tooth, one smaller adcauline tooth

344 ANNALS OF THE SOUTH AFRICAN MUSEUM

and sinuated margins which are deeply indented next to the abcauline tooth.

Median inferior nematotheca borne immediately below hydrotheca and

overreaching thecal base; two-chambered, immovable, distal chamber scoop-

shaped with no adcauline wall. Lateral nematotheca borne on long finger

shaped pedicel which reaches to level of thecal margin, two-chambered, movable;

distal chamber beaker-shaped and emarginated right to the base on medial side.

Median superior nematotheca situated behind free part of adcauline thecal wall

and usually pressed close against it, not reaching thecal margin, two-chambered,

with very short basal chamber and beaker-shaped distal chamber which is

deeply emarginated on adthecal side. Paired superior nematothecae seated

above median superior; those of hydrocladium smaller than median superior,

curved away from hydrotheca, situated behind free part of thecal wall; those of

stem larger, less curved and sometimes overreaching thecal margin; two-

chambered, movable.

Gonotheca (described here for the first time) borne on stem below hydro-

theca, whelk-shaped, with oblique aperture directed away from stem, with up to

five nematothecae on basal part, sex unknown.

Variation. Very rarely the distal part of an internode may be cut off by a trans-

verse node to form a short athecate intermediate internode. This may occur on

the stem or on the hydrocladia and the athecate internode takes with it a pair of

superior nematothecae. The last internode of a hydrocladium always terminates

at the level of the transverse node and lacks paired superior nematothecae.

Distribution outside South Africa. Madagascar. Type locality: Fort Dauphin.

Distribution in South Africa. One record only, off Scottburgh, Natal in 6-12 m.

30/30 (s)

Gattya heurteli (Billard, 1907)

Fig. 111J—L

Plumularia Heurteli Billard, 1907a: 360, figs 9-10.

Plumularia quadridentata Jarvis, 1922: 348, p.. 26 (fig. 22).

Paragattya heurteli: Millard, 1958: 208, fig. 10E.

Diagnosis. Main stem lightly fascicled at base, long and flexuous, reaching 180

mm, branching sparsely and irregularly. Axial tube of stem and branches

divided into internodes of irregular length by transverse nodes, giving rise to

alternate sub-branches (pinnae) at irregular intervals, without hydrothecae or

nematothecae.

Sub-branches (pinnae) unfascicled, consisting of a short basal part and a

long distal and hydrocladia-bearing part, the two separated by an oblique hinge-

joint. Basal part bearing 1-3 median nematothecae, often not sharply demarcated

from apophysis of stem. Distal part divided into internodes by oblique nodes.

The first internode thicker than the rest, terminated by a more distinct node and

bearing one pair of opposite hydrocladia; remaining internodes bearing alter-

nate hydrocladia, one to each. Each internode of distal part with one cauline

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 345

lames

( (O—9

)

Cie

y ; Q OU.

WwW bS y a

- Qe Se /

aaes

“ask Ce

o Z

eC hear

‘9

Fig. 111.

Gattya conspecta. A, stem in anterior view, including first internode and hinge-joint;

B, hydrocladium; C, gonotheca.

Gattya humilis. D and E, male and female gonophores respectively, the latter with planula;

F, pinnate stem in anterior view; G, hydrothecae; H, colony with pinnate and simple

stems.

Gattya heurteli. J, colony; K, anterior view of sub-branch (pinna); L, hydrothecae.

Scale: H and J in cm, the rest in mm/10.

346 ANNALS OF THE SOUTH AFRICAN MUSEUM

hydrotheca and four nematothecae, one median inferior, one pair laterals and

one median superior. Hydrocladial apophysis arising from process supporting

lateral nematotheca. The two rows of hydrocladia not in one plane but set on

the anterior surface of the pinna.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

short athecate internode, then up to five thecate internodes terminated by oblique

nodes. Thecate internodes without internodal septa, with four nematothecae,

one median inferior, one pair laterals and one median superior.

Hydrotheca deep cup-shaped, expanding slightly to margin, adnate for

over half adcauline length, abcauline wall straight, with no intrathecal septum,

0,12-0,3 mm in abcauline depth and 0,16—0,2 mm in marginal diameter. Margin

forming an angle of 50—60° with internode, with four marginal teeth, one median

abcauline, one median adcauline and one pair laterals, the lateral teeth closer

to the abcauline side.

Median inferior nematotheca well below hydrotheca, with margin not,

or only just, reaching thecal base; two-chambered, but basal chamber small,

immovable and not distinctly demarcated from internode, distal chamber scoop-

shaped, with no adcauline wall. Lateral nematotheca borne on a finger-shaped

pedicel, overtopping thecal margin, two-chambered, movable; distal chamber

flattened and deeply cut away at the narrow ends giving a bivalved appearance.

Median superior nematotheca seated behind free part of adcauline thecal wall

and not reaching margin, one-chambered, hook-shaped, immovable. Median

nematotheca on basal part of pinna similar to median inferior, but movable

and with longer basal chamber.

Gonophores unknown.

Variation. The two rows of sub-branches (pinnae) may be in one plane on the

stem, or the whole may be twisted in a loose spiral giving an irregular effect.

The basal part of the pinna may have 1-4 indistinct nodes, the last internode

being the longest and bearing the nematothecae.

Distribution outside South Africa. Tropical East Africa. Type locality: Macalonga

in Mocgambique, 22 m.

Distribution in South Africa. Natal and Mocgambique, 22-66 m, with one doubtful

record from Cape Town. ?33/18, 30/30 (s), 29/31 (s), 28/32 (s), 25/33 (s), 24/34 (s)

Gattya humilis Allman, 1886

Fig. 111D-H

Gattya humilis Allman, 1886: 156, pl. 24 (figs 5-7). Millard, 1962: 281.

Paragattya intermedia Warren, 1908: 323, fig. 16, pl. 47 (fig. 27).

Diagnosis. Hydrorhiza creeping, usually on weed. Colony capable of producing

two growth-forms, one in which hydrocladia arise from an erect stem, and one

in which hydrocladia arise independently from the hydrorhiza. Stem unfascicled,

unbranched, reaching 30 mm in height, consisting of a short basal part and a

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 347

long distal and hydrocladia-bearing part, the two separated by an oblique hinge-

joint. Basal part with 1-4 transverse nodes and sometimes one median nemato-

theca. Distal part divided into internodes by oblique nodes. The first internode

thicker than the rest, terminated by a more distinct node and bearing one pair

of opposite hydrocladia; remaining internodes bearing alternate hydrocladia,

one to each. Each internode with one cauline hydrotheca and four nemato-

thecae, one median inferior, one pair laterals and one median superior. Hydro-

cladial apophysis arising from process supporting lateral nematotheca. The

two rows of hydrocladia not in one plane but set on the anterior surface of the

stem.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

or two short athecate internodes, then up to three thecate internodes terminated

by oblique nodes. Thecate internodes without septa, with four nematothecae,

one median inferior, one pair laterals and one median superior.

Hydrotheca cup-shaped and deep, expanding to margin, adnate for about

half adcauline length, abcauline wall with a slight, but distinct, double curvature,

with no intrathecal septum, 0,19-0,3 mm in abcauline depth and 0,18-0,3 mm

in marginal diameter. Margin forming an angle of 50—60° with internode, with

four marginal teeth, one median adcauline, one median abcauline and one pair

laterals, the lateral teeth closer to the abcauline side.

Median inferior nematotheca immediately below hydrotheca, with margin

overreaching thecal base; two-chambered, but basal chamber small and

immovable, distal chamber scoop-shaped, with no adcauline wall. Lateral

nematotheca borne on a finger-shaped pedicel, overtopping thecal margin,

two-chambered, movable; distal chamber flattened, and deeply cut away at

the narrow ends giving a bivalved appearance. Median superior nematotheca

seated behind free part of adcauline thecal wall and not reaching margin, one-

chambered, similar in shape to the laterals.

Gonotheca borne on stem, and rarely on hydrocladium, immediately

below hydrotheca and on one side, pear-shaped, with two large nematothecae

on basal part, male and female on same stem but male more distal than female.

Female truncated distally and with a large terminal operculate aperture,

containing one egg which develops into a planula in situ. Male rounded distally,

with a small apical pore.

Variation. The species occurs commonly on coralline algae, but has also been

found on a sponge and on the crab, Dehaanius dentatus (M. Edw.).

Examples have been seen in which the hydrocladia branch in a similar

way to the stem. Other minor variations include the occurrence of intermediate

athecate internodes in the hydrocladia (Stechow 1925a), and a secondary point

to the lateral marginal tooth of the hydrotheca (Warren 1908).

Distribution. Endemic to South Africa. Type locality: ?Port Elizabeth.

Distribution in South Africa. Northern South West Africa on the west to Natal,

348 ANNALS OF THE SOUTH AFRICAN MUSEUM

littoral to 70 m. [19/12 (1)], 32/18 (s), 33/17 (1), 33/18 (1, s), 34/18 (1, s), 34/22 (s),

34/23, 33/25, 34/25 (s), 33/26 (s), 33/27 (1, s), 32/28 (s), 31/29 (I), 31/30 (),

30/30 (1)

Gattya multithecata (Jarvis, 1922)

Fig. 112A-B

Plumularia multithecata Jarvis, 1922: 346, pl. 25 (fig. 19).

Diagnosis. Stem unfascicled, unbranched, reaching 14 mm in height, consisting

of a short basal part and a long distal hydrocladia-bearing part, the two sepa-

rated by an oblique hinge-joint. Basal part with a few transverse nodes and

scattered nematothecae. Distal part divided by oblique nodes into thecate

internodes, of which the terminal part is often cut off by a transverse node to

form an intermediate athecate internode. The first thecate internode longer

and broader than the rest and bearing one pair of opposite hydrocladia; the

second thecate internode also bearing one pair of opposite hydrocladia; remain-

ing thecate internodes bearing alternate hydrocladia, one to each. Five to nine

nematothecae to each hydrotheca, one median inferior, one pair laterals, and

one to three pairs of superior; the last pair of superior seated on the following

athecate internode when this is present. Hydrocladial apophysis arising from

process supporting lateral nematotheca. The two rows of hydrocladia not in

one plane but set on the anterior surface of the stem.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

short athecate and anematothecate internode terminated by a straight node,

one short athecate internode bearing one median nematotheca and terminated

by an oblique node, then usually alternate long thecate internodes terminated

by straight nodes and short athecate intermediate internodes terminated by

oblique nodes. Up to nine hydrothecae to a hydrocladium. Thecate internodes

without septa, with four nematothecae, one median inferior, one pair laterals

and one median superior. Athecate intermediate internodes with one pair of

nematothecae.

Hydrotheca cup-shaped and deep, expanding to margin, adnate for a little

over half adcauline length, with no intrathecal septum, 0,2-0,3 mm in abcauline

depth and 0,18-0,2 mm in marginal diameter. Margin forming an angle of

about 40° with internode, with one strong inturned abcauline tooth, one smaller

adcauline tooth and sinuated lateral margins.

Median inferior nematotheca borne immediately below hydrotheca and

Overreaching thecal base; two-chambered, immovable, distal chamber scoop-

shaped with no adcauline wall. Lateral nematotheca borne on long, curved,

pedicel which reaches to level of thecal margin, two-chambered, movable;

distal chamber beaker-shaped; the whole emarginated to base of proximal

chamber on mesial side. Median superior nematotheca situated behind free

part of adcauline thecal wall, minute, two-chambered, with very short basal

chamber. Paired superior nematothecae of stem and nematothecae of athecate

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 349

internodes larger than median superior, curved, two-chambered, movable.

Gonothecae unknown.

Variation. The presence or absence of athecate intermediate internodes is

variable within the single colony known from the country. They are often present

on the stem, almost invariably on the hydrocladia. They are reported as present

in the type material.

Distribution outside South Africa. Tropical East Africa. Type localities: Zanzibar

and Wasin.

Distribution in South Africa. One record only, off Scottburgh, Natal in 6-12 m.

30/30 (s)

Genus Halopteris Allman, 1877

Syn. Heteroplon Allman, 1883.

Acladia Marktanner-Turneretscher, 1890.

Thecocaulus Bale, 1915.

Diagnosis. An erect stem present, usually (always, in South African species)

unfascicled and unbranched, if fascicled with one main axial tube, usually with

hinge-joints in basal region, bearing pinnately arranged hydrocladia and cauline

hydrothecae. Hydrocladia alternate or in opposite pairs, but usually with at

least the first one or two pairs opposite, sometimes (as a secondary growth-form)

arising independently from hydrorhiza, normally unbranched. Hydrotheca

cup-shaped, with untoothed margin.

Type species: Halopteris carinata Allman, 1877.

KEY TO SPECIES

(For simple forms see also under Antennella, p. 330)

1. Stem heteromerous, with alternate thecate, hydrocladiate internodes and athecate,

ahydrocladiate internodes .. 2

— Stem normally homomerous, with all internodes thecate and hydrocladiate; ‘may be

unsegmented .. oe vel a de big ne sits aa seis fy

2. Hydrotheca with even margin; free part of adcauline wall concave Hf. pseudoconstricta

Hydrotheca raised into a beak-like process on abcauline edge; free part of adcauline

wall straight .. Bs ~ be We ae ait = es H. rostrata

3. All hydrocladia in opposite pairs. Lateral nematothecae one-chambered JH. gemellipara

Hydrocladia alternate (except for the first one or two pairs which may be opposite).

Lateral nematothecae two-chambered . .

4. Lateral nematotheca with distal chamber wineglass-shaped and deeply emarginated

on mesial side i H. glutinosa

— Lateral nematotheca with distal chamber funnel- shaped and not deeply emarginated,

though the mesial edge may be lower than the lateral edge =f a Ets

5. No superior nematothecae on hydrocladial internodes .. a H. tuba

Two superior nematothecae on hydrocladial internodes, one behind hydrotheca and

one above it, the latter sometimes cut off on a separate athecate internode H. polymorpha

350 ANNALS OF THE SOUTH AFRICAN MUSEUM

he!

Woke iS

(

ies,

ibe

es (S

co.

“y

(cane

Jere) J,

Gattya multithecata. A, stem in anterior view; B, hydrothecae.

Halopteris gemellipara. C, hydrothecae; D, stem in anterior view; E, lateral nematotheca;

F, stem.

Halopteris polymorpha. G and H, lateral nematothecae; J, stem; K, hydrothecae; L, stem

in anterior view.

Scale: F and J in cm, the rest in mm/10.

MONUGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 351

Halopteris gemellipara Millard, 1962

Fig. 112C—F

Halopteris gemellipara Millard, 1962: 283, fig. 4A—F.

Diagnosis. Stem reaching 60 mm in height, consisting of an athecate basal

part and a distal thecate and hydrocladia-bearing part. No hinge-joints. Basal

part with a variable number of transverse nodes and median nematothecae.

Distal part divided into long thecate internodes by oblique nodes. Cauline

hydrothecae in one row on front of stem, one on the proximal part of each

internode. Hydrocladia in opposite pairs, one pair to each internode, arising

from the sides of the hydrothecae by short apophyses. Each internode with

five to seven nematothecae, one median inferior, one pair laterals and two to

four median superior.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

short athecate internode bearing one median nematotheca and then up to 11

thecate internodes terminated by oblique nodes. No internodal septa. Each

thecate internode with three to four nematothecae, one median inferior, one pair

laterals, and sometimes one median superior.

Hydrotheca cup-shaped, adnate for 4-3? height (usually about 3), with

parallel walls flaring slightly to margin, with no intrathecal septum, 0,2—-0,5 mm

in abcauline height and 0,2-0,3 mm in marginal diameter. Margin forming an

angle of 50—70° with internode.

Median inferior nematotheca not reaching base of hydrotheca, two-

chambered, immovable; basal chamber smaller than distal and not distinctly

demarcated from internode; distal chamber scoop-shaped, with no adcauline

wall. Lateral nematotheca borne on low protuberance of internode, not reaching

thecal margin, minute, immovable, one-chambered, with emarginated mesial

wall. Median superior nematotheca, when present, seated above level of thecal

margin, similar to median inferior but with more convex abcauline wall, those of

stem larger than those of hydrocladium.

Gonothecae unknown.

Variation. Occasionally the distal end of a thecate internode may be cut off by a

transverse node to form an intermediate athecate internode. This is more com-

mon near the distal ends of the hydrocladia. One stem has been seen bearing

a pair of hydrocladia on the posterior surface in addition to those on the anterior

surface.

The hydrotheca may have a diameter more or less equal to the height and

be set at a comparatively wide angle to the internode, or it may have a diameter

of about half the height and be set almost parallel to the internode.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 33°54'S/

26°51 E, 120 m.

Distribution in South Africa. South-east coast, from Port Elizabeth to Durban,

49-120 m. 34/25 (s), 33/26 (d), 33/27 (s), 32/28 (s), 29/31 (s)

352 ANNALS OF THE SOUTH AFRICAN MUSEUM

Halopteris glutinosa (Lamouroux, 1816)

Fig. 113

Aglaophenia Glutinosa Lamouroux, 1816: 171.

Heteroplon pluma Allman, 1883: 32, pl. 8 (figs 1-3).

Plumularia glutinosa: Billard, 1910: 36, fig. 16.

Plumularia alternata: Jarvis, 1922: 345, pl. 25 (fig. 16).

Plumularia (Heteroplon) glutinosa: Stechow, 1925a: 502.

Halopteris glutinosa: Millard, 1958: 200, fig. 1OA—D. Millard, 1962: 285, fig. 4K.

Diagnosis. Stem capable of reaching 180 mm though more commonly 10-40

mm, consisting of an athecate basal part and a distal thecate and hydrocladia-

bearing part, the two sometimes separated by an oblique hinge-joint, a second

hinge-joint sometimes present after the first hydrotheca. Basal part with a

variable number of transverse nodes and nematothecae. Distal part usually

divided into thecate internodes by oblique nodes. Cauline hydrothecae usually

in one row on front of stem, one to an internode. One or two pairs of opposite

hydrocladia arising by short apophyses at the sides of the first one or two hydro-

thecae; remaining hydrocladia alternate, one to each hydrotheca. At least four

nematothecae to each internode, one median inferior, one pair laterals, one

median superior; one to three extra pairs of laterals and one to two extra median

superior sometimes present.

Hydrocladium bearing hydrothecae obliquely (intermediate between upper

and anterior surface), consisting of one very short athecate and anematothecate

internode terminated by a slightly oblique node, one longer athecate internode

bearing one median nematotheca and terminated by a steeply oblique node,

and then up to 15 thecate internodes terminated by oblique nodes. No internodal

septa. Each thecate internode with three to six nematothecae, one median

inferior, one pair laterals, up to two, or rarely three, median superior.

Hydrotheca cup-shaped, adnate for 4-2 height, with walls straight or flaring

slightly to margin, with no intrathecal septum, 0,15-0,3 mm in abcauline height

and 0,19-0,4 mm in marginal diameter. Margin forming an angle of 30—60°

with internode.

Median inferior nematotheca not, or only just, reaching base of hydrotheca,

two-chambered, with basal chamber immovable and not sharply demarcated

from internode, distal chamber scoop-shaped, with no adcauline wall. Lateral

nematotheca borne on finger-shaped pedicel, not quite reaching thecal margin,

two-chambered, movable; distal chamber wineglass-shaped and deeply emar-

ginated on mesial side. Superior nematotheca seated behind free part of

adcauline thecal wall, variable in structure and size, one- or two-chambered.

Male and female gonothecae borne on same colony, the female on the

stem and the male on the hydrocladia, arising immediately below hydrotheca.

Female gonotheca large, flattened antero-posteriorly, elongate-oval in front view,

with broad distal aperture; with two to five large nematothecae on basal part;

pedicel of one segment. Male gonotheca spindle-shaped.

Variation. This is one of the most variable species of Halopterinae, and its

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 353

para

Fig. 113.

Halopteris glutinosa. A, stem in anterior view; B, lateral nematotheca; C, stems; D, female

gonotheca; E, male gonotheca; F, hydrocladium.

Scale: C in cm, the rest in mm/10.

354 ANNALS OF THE SOUTH AFRICAN MUSEUM

most useful diagnostic character is the structure and size of the lateral

nematotheca.

The stem varies greatly in length and thickness, and in the older, thicker

stems nodes may be absent and the hydrothecae may be displaced alternately

to left and right. In some stems nodes occur after every two hydrothecae. Some-

times extra hinge-joints, probably due to regeneration after injury, occur in the

basal part of the stem.

In the distal region of both stem and hydrocladia the distal ends of the

internodes may be cut off by transverse nodes above the level of the hydrotheca

to form intermediate athecate internodes. These may carry one median

nematotheca. Several examples of branched hydrocladia have been observed.

The hydrothecae are also extremely variable in size, though their shape

and proportion remains constant.

Distribution outside South Africa. Bass Strait, South Australia; Gulf of Aqaba;

tropical East Africa. Type locality: “Mers des Indes et de |’Australasie’.

Distribution in South Africa. Fairly common on south and east coasts, from off

Still Bay to Inhaca in Mocambique, littoral to 411 m. 34/21, 35/21 (d), 34/22 (s),

34/24 (d), 33/25 (s), 34/25 (s, d), 33/26 (s), 33/27 (Ss), 32/28 (s), 33/28 (s), 31/29

(s), 30/30 (s), 29/31 (1, s, d), 28/32 (s, d), 26/32 (, s)

Halopteris polymorpha (Billard, 1913)

Fig. 112G—-L

Plumularia polymorpha Billard, 1913: 24, figs 14-15.

Halopteris polymorpha: Vervoort, 19665: 132, fig. 35. Millard & Bouillon, 1973: 83, fig. 10F—J.

Diagnosis. Stem reaching 82 mm in height, consisting of an athecate basal

part and a distal thecate and hydrocladia-bearing part, the two separated

by an oblique hinge-joint, a second hinge-joint usually present after the first

hydrotheca. Basal part with a variable number of transverse nodes and nemato-

thecae. Distal part divided into thecate internodes by oblique nodes. Cauline

hydrothecae in one row on front of stem, one to each internode. Hydrocladia

alternate, one arising by a short apophysis at the side of each hydrotheca;

usually a pair of opposite hydrocladia on the first and second thecate internodes.

At least five nematothecae to each internode one median inferior, one palit

laterals and two median superior; one or more extra pairs often present above

level of hydrotheca.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

one short athecate and anematothecate internode terminated by a straight node,

one long athecate internode bearing one median nematotheca and terminated

by a steeply oblique node, then up to nine thecate internodes terminated by

oblique nodes. No internodal septa. Each thecate internode with five nemato-

thecae, one median inferior, one pair laterals and one or two median superior.

The distal part of the thecate internode often cut off as a separate athecate

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 355

intermediate internode, carrying with it the second median superior nema-

totheca.

Hydrotheca cup-shaped, adnate for 3—3 height, with straight walls widening

slightly to margin, with no intrathecal septum, 0,17—0,3 mm in abcauline height

and 0,18—0,3 mm in marginal diameter. Margin forming an angle of about 50°

with internode. :

Median inferior nematotheca not, or only just, reaching base of hydrotheca,

two-chambered, immovable; distal chamber scoop-shaped, with no adcauline

wall. Lateral nematotheca borne on finger-shaped pedicel, reaching approxi-

mately to thecal margin or above it, two-chambered, movable; distal chamber

funnel-shaped, with lower mesial wall. First superior nematotheca behind free

part of adcauline thecal wall, minute, one-chambered, immovable. Second

superior nematotheca seated behind or above thecal margin, two-chambered,

movable; distal chamber scoop-shaped with low adcauline wall.

Gonothecae arising immediately below hydrothecae, with curved pedicel

of one segment. Female large, flattened, pear-shaped in broad view, bearing

two nematothecae, containing one egg. Male smaller, curved-oval, bearing

one nematotheca.

Variation. Billard has commented on the variability of this species and this is

substantiated by the few samples known from South Africa. The most obvious

variation is the presence or absence of a node separating off an intermediate

internode from the distal end of a thecate internode. Normally such nodes

occur only in the hydrocladia, but rarely also in the distal end of the stem.

The first athecate internode of the hydrocladium may not be distinctly demar-

cated from the second, as in Vervoort’s material. Several branching hydrocladia

have been seen. Up to five pairs of opposite hydrocladia may occur at base of

stem.

The proportions of the hydrothecae vary, sometimes they are deeper than

wide, and sometimes wider than deep, both shapes illustrated by Billard (fig.

14) occurring. The first superior nematotheca behind the thecal wall is sometimes

absent on the hydrocladia.

Distribution outside South Africa. Indian Ocean: Borneo Bank and south of

Island of Rotti (type locality), East Indies, Seychelles, Red Sea. Pacific Ocean:

New Caledonia.

Distribution in South Africa. Natal to Mocambique, littoral to 495 m. 29/31

(Gare) 29) 3258) 28/326) 27/32. (@)5, 26/325, 25/32, 21/35

Halopteris pseudoconstricta sp. nov.

Fig. 114D-G

Halopteris constricta: Millard, 1957: 227, fig. 14A. Millard, 1962: 282, fig. 4G. Millard, 19665:

493.

non Halopteris constricta Totton, 1930: 217, fig. 56a. Ralph 19615: 43, fig. 6a.

Type. Designated holotype: SAM-—H542: material from intertidal region at

356 ANNALS OF THE SOUTH AFRICAN MUSEUM

Melkbosstrand, Table Bay, collected 17/11/67. Numerous pinnate stems bearing

female gonophores and reaching a maximum height of 7 mm. Simple forms

also present and a few pinnate stems with branched hydrocladia.

Diagnosis. Colony capable of producing two growth-forms, one in which

hydrocladia arise from an erect stem, and one in which hydrocladia arise

independently from the hydrorhiza. Stem reaching 9 mm in height, consisting

of a short basal part and a long distal and hydrocladia-bearing part, the two

separated by an oblique hinge-joint. Basal part with a variable number of trans-

verse nodes and median nematothecae. Distal part divided into alternate thecate

and athecate internodes terminated by straight and steeply oblique nodes

respectively. Hydrocladia alternate, one to each thecate internode, with some-

times an opposite pair on the first and second thecate internodes, arising from

the pedicels of the lateral nematothecae. Thecate internodes with three or four

nematothecae, one median inferior, one pair laterals and sometimes one median

superior; athecate internodes with one or two median nematothecae.

Hydrocladium bearing up to six hydrothecae on anterior surface, con-

sisting of one or two short athecate and anematothecate internodes terminated

by slightly oblique nodes, one longer athecate internode bearing one or two

median nematothecae and terminated by a steeply oblique node, and then

alternate long thecate and short athecate internodes terminated by straight

and oblique nodes respectively. No internodal septa. Each thecate internode

with three nematothecae, one median inferior and one pair laterals. Each

athecate internode with one, and sometimes two median nematothecae.

Hydrotheca cup-shaped, adnate for 4-3 height, with straight abcauline

wall and with distinct concavity in free part of adcauline wall, with no intra-

thecal septum, 0,14-0,20 mm in abcauline height and 0,09-0,17 mm in marginal

diameter. Margin forming an angle of 40—60° with internode.

Median inferior nematotheca not reaching base of hydrotheca, two-

chambered, with basal chamber immovable and not distinctly demarcated

from internode, distal chamber scoop-shaped, with low adcauline wall. Lateral

nematotheca borne on a short papilla-shaped pedicel, not quite reaching thecal

margin, two-chambered, movable; distal chamber funnel-shaped, not emargi-

nated but with a lower mesial wall. Median superior nematotheca, when

present, seated behind free part of adcauline thecal wall, this and the nemato-

thecae on athecate intermediate internodes two-chambered, movable.

Female gonothecae borne on stem or hydrocladia immediately below hydro-

thecae singly or in pairs, laterally compressed, curved-pear-shaped in side

view, with broad distal aperture facing towards stem, containing one egg on

side of blastostyle which develops into a planula in situ; with two large nemato-

thecae on basal part; reaching 0,66 mm in length and 0,40 mm in maximum

diameter. Pedicel of one segment. Male gonotheca unknown.

Variation. In addition to the variations included in the diagnosis, pinnate stems

have been seen with hydrocladia which branch in a similar manner to the stem.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA S57

The margin of the hydrotheca is sometimes thickened on the abcauline

side, and may also be narrowed.

In some cases the distal part of a thecate hydrocladial internode*may be

cut off as an extra athecate internode.

Remarks. This material was previously assigned to Halopteris constricta, a

species first described by Totton from infertile material from New Zealand.

The female gonophores were described by Ralph (19615). These are curved in a

sigmoid manner and have their apertures directed away from the stem. At

this stage a paper was already in the press by the present author describing

female gonophores in the South African material. These are pear-shaped and

have their apertures directed towards the stem. On the basis of this difference

in the gonophores it is now necessary to create a new species for the South

African material. There is little to distinguish the trophosomes of the two

species, but neither simple forms nor branched hydrocladia have been observed

in the New Zealand material.

Distribution outside South Africa. Angola and Vema Seamount (South Atlantic).

Distribution in South Africa. Table Bay to Transkei coast, littoral to 19 m.

33/18 (1), 34/18 (1, s), 34/22 (s), 34/25 (s), 31/29 (1)

Halopteris rostrata sp. nov.

Fig. 114A—C

Material. The holotype, SAM—H543, consists of a colony of 11 complete stems

and a number of damaged ones growing over the skeleton of an antipatharian

coral. Position: off Natal, 29°11’S/32°02’E, 70 m, 30/7/1964.

Description. Hydrorhiza creeping and branching, giving rise to erect stems.

Stems unfascicled, unbranched, the tallest 11 mm in height, with a short basal

part devoid of hydrothecae and hydrocladia but sometimes with one or two

nematothecae, and a longer distal part bearing hydrocladia and hydrothecae.

No hinge-joints. Distal part divided into regularly alternate long thecate and

short athecate internodes terminated by straight and oblique nodes respectively,

the first thecate internode bearing a pair of opposite hydrocladia arising from

the sides of the hydrotheca, remaining hydrocladia alternate, one from the

side of each hydrotheca alternately on the left and the right. Stem geniculate

in terminal part. Hydrothecae in one row on front of stem, but with their

apertures directed alternately to left and right (to the same side as the corres-

ponding hydrocladium). Each thecate internode with three nematothecae, one

median inferior and one pair laterals, of which one is in the axil of the

hydrocladium. Each athecate internode with one median nematotheca.

Hydrocladium bearing one to five hydrothecae on anterior face, with one

short athecate and anematothecate internode terminated by a slightly oblique

node, then alternate short athecate and long thecate internodes terminated by

oblique and straight nodes respectively. Each thecate internode with one hydro-

358 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 114.

Halopteris rostrata sp. nov., all from holotype. A, hydrothecae; B, lateral nematotheca in

medial view; C, stem in anterior view (the basal pair of hydrocladia broken off).

Halopteris pseudoconstricta sp. nov. D, hydrocladium; E, stem in anterior view; F, lateral

nematotheca; G, female gonothecae.

Scale in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 359

theca and three nematothecae, one median inferior and one pair laterals. Each

athecate internode, other than the first, with one median nematotheca.

Hydrotheca cup-shaped in side view, with straight walls widening to

margin, more or less conical in anterior view, adnate for about half height and

with free part of adcauline wall overlapping subsequent athecate internode.

Margin forming an angle of 50-60° with internode, more or less even on pos-

terior and lateral edges, but rising into a beak-like lobe on anterior (abcauline)

edge; abcauline edge sometimes thickened.

Median inferior nematotheca seated below hydrotheca and reaching

approximately to the level of its base, though sometimes a little above or below,

two-chambered, immovable; basal chamber small and inconspicuous; distal

chamber scoop-shaped, with no adcauline wall. Lateral nematotheca seated on

a short, rounded process applied to the lateral wall of the hydrotheca, just, or

not quite, reaching thecal margin, two-chambered, movable; basal chamber

shorter than distal; distal chamber wineglass-shaped, with very deep emargina-

tion on mesial surface. Lateral nematothecae of stem shorter than those on

hydrocladia and not reaching thecal margin. Median nematotheca of athecate

internode two-chambered, movable, often obscured by adcauline wall of hydro-

theca, basal and distal chamber of approximately equal size; distal chamber

scoop-shaped, with low adcauline wall.

Gonothecae absent.

Measurements (mm)

Hydrocladium, thecate internode, length a id be .. 0,29-0,38

athecate internode other than first, length i ih .. 0,12-0,17

Hydrotheca, depth abcauline A ie iy re i: .. 0,17-0,29

diameter at margin .. dd — an fe oe .. 0,23-0,34

free part adcauline wall/abcauline height .. oe Ag, .. 0,31-0,59

Lateral nematotheca, length ft 1 ae ae = .. 0,09-0,12

Remarks. The shape of the hydrotheca is reminiscent of that in H. carinata

Allman, 1877, Gattya multithecata (Jarvis, 1922) and Gattya trebilcocki Watson,

1973. All of these have lateral nematothecae overtopping the thecal margin and

seated on long pedicels; that of H. carinata is one-chambered. There are also

other differences in the complement of nematothecae and the margin of the

hydrotheca of these three species.

H. rostrata, with its lobed thecal margin, shows tendencies towards the

genus Gattya.

Distribution. Endemic to South Africa.

Distribution in South Africa, off Natal, 70-100 m. 29/31 (s), 29/32 (s), 28/32 (d)

Halopteris tuba (Kirchenpauer, 1876)

Fig. 115

Plumularia tuba Kirchenpauer, 1876: 44, pl. 1 (fig. 2), pl. 4 (figs 2—2d).

Heteroplon jaederholmi Stechow, 1912: 366, figs F—G.

Plumularia (Heteroplon) africana: Stechow, 1925a: 500, figs 44-45.

Halopteris tuba: Millard, 1962: 286, fig. 5.

360 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis. Stem reaching 220 mm in height, consisting of an athecate basal

part and a distal thecate and hydrocladia-bearing part, the two usually separated

by an oblique hinge-joint, a second hinge-joint sometimes present after the

first hydrotheca. Basal part with a variable number of transverse nodes and

nematothecae. Distal part normally unsegmented, but with faint transverse or

slightly oblique nodes sometimes visible near tip, bearing hydrothecae on

anterior face, the first two median, the rest displaced alternately to left and right

and forming two longitudinal rows. Two pairs of opposite hydrocladia arising

by short apophyses at the sides of the first two hydrothecae; remaining hydro-

cladia alternate, one to each hydrotheca. Five nematothecae corresponding to

each hydrotheca, one median inferior, one pair laterals, and one pair superior;

the median inferior not directly below the hydrotheca, but displaced to the

opposite side so that it lies above the previous hydrotheca; one or more extra

nematothecae between hinge-joints.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

short athecate internode bearing one median nematotheca and terminated by an

oblique node and then up to 13 thecate internodes terminated by oblique nodes.

Two internodal septa (one proximal and one distal) sometimes present in old

colonies. Each thecate internode with three nematothecae, one median inferior

and one pair laterals, and also one median superior naked sarcophore behind

posterior wall of hydrotheca. |

Hydrotheca cup-shaped, shallow, with depth usually less than diameter, with

straight walls, almost completely adnate, 0,09-0,20 mm in abcauline height and

0,14-0,3 mm in marginal diameter on hydrocladium; cauline hydrotheca

normally with thickened perisarc and eroded margin, thus shallower and with

no free part. Margin forming an angle of 50—70° with internode.

Median inferior nematotheca well below hydrotheca and not reaching its

base, two-chambered, immovable; basal chamber not distinctly demarcated

from internode; distal chamber scoop-shaped, with no adcauline wall. Lateral

nematotheca large, reaching well above thecal margin, two-chambered, movable;

distal chamber funnel-shaped and not emarginated; those on hydrocladium

seated on rounded pedicel, those of stem larger, not pedicellate. Superior nema-

tothecae of stem seated above adnate part of thecal wall, minute, hook-shaped,

one-chambered, immovable.

Gonothecae borne on hydrocladia below hydrothecae, male and female

on same stem, but male more distal than female. Female gonotheca flattened

anterior-posteriorly, oval in front view, containing one, or rarely two, eggs

between the limbs of a bifurcating blastostyle, eggs developing into planulae

in situ; with three large nematothecae on basal part; pedicel of one segment.

Male gonotheca elongate-oval, curved.

Variation. Apart from variations included in the diagnosis there may occasionally

be more than two pairs of opposite hydrocladia on the stem.

In some cases there may be an extra, short athecate internode at the base

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 361

AM F G

Pig. 115.

Halopteris tuba. A, stem; B, proximal end of hydrocladium; C, lower part of stem in anterior

view, with hinge-joints; D, male gonothecae; E, female gonotheca; F and G, cauline

hydrothecae, F from a lower level on the stem, showing paired superior nematothecae

(aperture for lateral nematotheca on left of hydrotheca).

Scale: A in cm, the rest in mm/10.

362 ANNALS OF THE SOUTH AFRICAN MUSEUM

of the hydrocladium, representing part of the apophysis which has been cut off.

Rarely deeper hydrothecae occur, when the depth equals the marginal

diameter.

Distribution. Endemic to South Africa. Type locality: Algoa Bay.

Distribution in South Africa. South and east coasts from False Bay to Natal,

in 11-550 m. Fairly common. 34/18 (s), 34/19 (s), 35/20 (d), 34/21 (s), 34/22

(s), 35/22 (d, vd), 34/23 (s, d), 34/24 (d), 33/25 (s), 34/25 (s, d), 33/26 (s), 33/27

(s), 33/28 (s), 32/28 (s), 30/31 (s), 29/31 (, d)

Genus Monostaechas Allman, 1877

Diagnosis. An erect stem present or absent. If present and fascicled, stem com-

posed of intercommunicating tubes of equal diameter and importance which

give rise irregularly to hydrocladia. If stem absent, hydrocladia arising directly

from hydrorhiza. Hydrocladia branching in the form of a sympodium, either

dichotomous or helicoid, in the latter case branching from the posterior surface.

Hydrotheca cup-shaped, with untoothed margin.

Type species: Monostaechas dichotoma Allman, 1877 (= Plumularia quadridens

McCrady, 1857).

KEY TO SPECIES

(For simple forms, see also under Antennella, p. 330)

1. Hydrotheca completely adnate, margin at right angles to hydrocladium M. faurei

Hydrotheca not completely adnate, margin directed obliquely outwards. a ae t

2. Subsidiary hydrocladium adnate to previous one for a short distance and then

forming a small angle with it (under 30°) . se M. natalensis

— Subsidiary hydrocladium not adnate to previous one and forming a iaee angle with

it (OVER30 = ae she ae a = *. Wy 7 M. guadridens

Monostaechas faurei Millard, 1958

Fig. 116A—D

Monostaechas faurei Millard, 1958: 204, fig. 11. Millard, 1968: 277, fig. 5E.

Diagnosis. Stem fascicled, reaching 142 mm, branching in a roughly dichotomous

manner, its component tubes diverging from one another to form hydrocladia

in an irregular fashion.

Hydrocladia branching sympodially from the posterior surface, the whole

Sympodium curved backwards in one plane. Hydrocladium consisting of a

short basal athecate part terminated by an oblique node and a long distal

thecate part divided into thecate internodes by oblique nodes. The basal part

of a subsidiary hydrocladium very characteristic: originating from previous

hydrocladium immediately below the first oblique node of the latter; its first

internode almost entirely adnate to posterior surface of the first thecate inter-

node of the previous hydrocladium and communicating with it by a pore near

the distal end, then free for a short distance and terminated by a transverse

node; second internode free, bearing a double series of nematothecae, termi-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 363

nated by an oblique node. Each thecate internode bearing one hydrotheca and

nine nematothecae, one median inferior and four pairs laterals.

Hydrotheca deep-campanulate, completely adnate, 0,18-0,3 mm in height

and 0,11-0,15 mm in marginal diameter. Margin at right angles to internode.

Nematothecae all large, two-chambered and movable; distal chamber

funnel-shaped, with adcauline edge lower than abcauline. Median inferior

nematotheca not, or only just, reaching base of hydrotheca. Lateral nemato-

thecae: first pair borne on long finger-shaped pedicels at sides of hydrotheca

but not reaching thecal margin, second pair borne in axils of pedicels of first

pair, third pair arising at sides of hydrotheca and overtopping thecal margin,

fourth pair arising above level of hydrotheca and overreaching next oblique

node.

Gonothecae borne on hydrocladia below hydrothecae, male and female

on the same colony, the male more distal than the female, curved-pear-shaped,

pedicel of one segment. Female gonotheca with wide and operculate distal

aperture, bearing 2—5 large nematothecae near base, containing one or two

planulae. Male gonotheca smaller than female, with rounded distal end, bearing

two large nematothecae near base.

Variation. The first hydrotheca of a hydrocladium is distinctly shallower than

the rest. Occasionally the distal end of a hydrocladial internode may be cut off

by a transverse node to form an intermediate athecate internode, causing some

irregularity in the nematothecae.

Distribution. Endemic to South Africa. Type locality: off Natal, approximately

28°41°S/32°22’E, 62 m.

Distribution in South Africa. On the east coast, from East London to St. Lucia,

49-219 m. 33/28 (s), 30/31 (s), 29/31 (s, d), 28/32 (s, d)

Monostaechas natalensis Millard, 1958

Figs 116E-G, 117A-—C

Monostaechas natalensis Millard, 1958: 206, fig. 12. Millard, 1962: 291, fig. 2F.

Diagnosis. Colony reaching a maximum height of 76 mm, though more often

under 30 mm, consisting of either numbers of hydrocladia arising in tufts

from a short fascicled stem or separate hydrocladia arising independently from

the hydrorhiza. The component tubes of the stem diverging to form branches

and hydrocladia.

Hydrocladium unbranched or branching sympodially once or twice from

posterior surface; consisting of a short basal athecate part terminated by an

oblique node and a long distal thecate part divided into thecate internodes by

oblique nodes. Basal part containing one or two transverse nodes and bearing

a double series of nematothecae. A subsidiary hydrocladium arising from pre-

vious one at any level and forming an acute angle with it, adnate to it for a

short distance and with or without a second communicating pore. Each thecate

ANNALS OF THE SOUTH AFRICAN MUSEUM

364

Sei cal eI creat a

Fig. 116.

Monostaechas faurei. A, branching hydrocladium; B, stem; C, hydrocladium with male

gonotheca; D, hydrocladium with female gonotheca.

Monostaechas natalensis. E, hydrocladium; F, branching hydrocladia; G, lateral nema

tothecae.

Scale: B in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 365

internode bearing one hydrotheca and six to ten nematothecae, one median

inferior, two pairs laterals and one to five superior.

Hydrotheca campanulate, generally adnate for over half height, with no

intrathecal septum, 0,16-0,6 mm in height and 0,15-0,4 mm in marginal

diameter. Margin forming an angle of about 65° with internode.

Nematothecae all two-chambered and movable. Median inferior nemato-

theca not reaching base of hydrotheca. Lateral nematothecae: first pair borne

on long finger-shaped pedicels at sides of hydrotheca but not reaching thecal

margin; second pair borne in axils of pedicels of first pair; in both distal chamber

funnel-shaped and deeply emarginated on two sides forming a bivalve structure

with a large abcauline and a very small adcauline valve. Superior nematothecae

variable in number and position, sometimes one or a pair arising behind free

part of thecal wall and overtopping margin, sometimes one to three median

arising above level of thecal margin.

Gonothecae borne on hydrocladia below hydrothecae, male and female

on same colony, the male more distal than the female, curved pear-shaped,

pedicel of one segment, bearing two nematothecae near base. Female gono-

theca with wide and operculate distal aperture. Male gonotheca smaller than

female, with rounded distal end.

Variation. This species is very variable in its growth-form, the larger colonies

possessing rugged stems which branch irregularly and give rise to spectacular

sprays of hydrocladia; the smaller colonies consisting of low tufts of hydro-

cladia arising from an agglomeration of stem-tubes, and many solitary

hydrocladia.

The tendency for the hydrocladia to branch sympodially is not as strong as

in M. faurei and the species appears to be intermediate between the genera

Monostaechas and Corhiza. Its ability to produce solitary hydrocladia indicates

affinity with Antennella.

Occasionally the distal end of a thecate internode may be cut off by a

transverse node to form an intermediate athecate internode, taking with it one

or two of the superior nematothecae.

Distribution. Endemic to South Africa. Type locality: off Natal, 30°32’S/

30°38,5’E, 46 m.

Distribution in South Africa. On the south and east coasts, from Port Elizabeth

to Inhambane, 18-150 m. 34/25 (s, d), 33/28 (s), 31/29 (s), 30/30 (s), 29/31 (s),

28/32 (s), 24/34 (s), 24/35 (s)

Monostaechas quadridens (McCrady, 1858)

Fig. 117D-F

Plumularia quadridens McCrady, 1858: 97.

Monostaechas dichotoma Allman, 1877: 37, pl. 22 (figs 1-5).

Monostaechas quadridens: Nutting, 1900: 75, pl. 13 (figs 1-4). Stechow, 19255: 252. Vervoort,

1968, 61, fig. 28.

Monostaechas fisheri var. simplex Billard, 1913: 16, fig. 7.

366 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis. Colony reaching a maximum height of 15 mm, consisting of hydro-

cladia which arise separately from the hydrorhiza and branch sympodially.

Larger colonies branching first in the form of a dichotomous sympodium,

in which two subsidiary hydrocladia of equal diameter arise from opposite

sides of the primary one; later branching in the form of a helicoid sympodium,

in which each subsidiary hydrocladium arises from the posterior surface of the

previous one. Smaller colonies branching as a helicoid sympodium only.

Subsidiary hydrocladia always facing towards the previous one, thus all hydro-

cladia of a helicoid sympodium in one plane, but not those of a dichotomous

sympodium. False axis of helicoid sympodium straight or curved backwards,

formed by the bases of successive hydrocladia.

Each hydrocladium consisting of a basal unsegmented athecate part bearing

a variable number of nematothecae, and a distal thecate part, the two separated

by an oblique node; with a distinct forward bend of 140-160° just below the

oblique node, from which region the next hydrocladium arises. Distal part of

hydrocladium consisting of alternate thecate and athecate internodes termi-

nated by transverse and oblique nodes respectively, though the transverse

nodes may be very poorly defined in certain areas. Each thecate internode

bearing one hydrotheca and four nematothecae, one median inferior, one pair

laterals and one median superior. Each athecate internode bearing two median

nematothecae.

Hydrotheca cup-shaped, adnate for about half height, with no intrathecal

septum, 0,2—-0,3 mm in height and 0,2-0,3 mm in marginal diameter. Margin

forming an angle of 30-60° with internode.

Median inferior nematotheca not quite reaching base of hydrotheca,

possibly movable, two-chambered; distal chamber scoop-shaped, with low

adcauline wall. Lateral nematothecae borne on finger-shaped pedicels at sides

of hydrotheca and not quite reaching thecal margin, two-chambered, movable;

distal chamber funnel-shaped. Median superior nematotheca seated behind

free part of thecal wall, minute, one-chambered. Nematothecae of athecate

internodes similar to median inferior, movable.

Gonothecae borne on hydrocladia below hydrothecae, male and female

on same colony, curved pear-shaped, pedicel of two segments, bearing two

nematothecae near base. Female with wide operculate distal aperture, containing

a single egg. Male smaller than female and with smaller aperture.

Variation. Most of the South African stems have the helicoid sympodium only,

but a few show the dichotomous sympodium at the base. The ‘dichotomy’

is not as regular as in the type area (West Indies) as figured by Allman, and the

two subsidiary hydrocladia may arise side by side from the posterior surface

of the previous one, or one from the lateral surface and one from the posterior

surface.

Distribution outside South Africa. Circumglobal in tropical and temperate waters.

Type locality: Charleston, U.S.A.

367

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

A,C,D,F

x A : 9 J

Y \ 4 i

g 2 i IM i of i

aes HQ i

rene GQ \\p W

Y \ 4 e \h J]

\ ~ ane, CO a.

Ra LA

Fig. 117.

Monostaechas natalensis. A, male gonotheca; B, stem; C, part of hydrocladium with female

gonotheca.

Monostaechas quadridens. D, male gonotheca; E, two stems, the one on the left branching

first dichotomously and then in a helicoid manner, the one on the right branching as a

helicoid sympodium only; F, hydrocladium with female gonotheca.

Scale: B in cm, the rest in mm/10.

368 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. Natal to Mocgambique, littoral and 0-70 m. 31/30

(1), 30/30 (s), 29/31 (s), 29/32 (s), 28/32 (s), 26/32, 25/32, 21/35

Genus Schizotricha Allman, 1883

Diagnosis. An erect stem present, which may be branched or unbranched,

fascicled or unfascicled; if fascicled with one main axial tube bearing pinnately

arranged hydrocladia; with cauline hydrothecae. Hydrocladia alternate, at

least some of them branching sympodially from anterior or lateral surface

immediately below hydrothecae. Hydrotheca cup-shaped, with untoothed

margin.

Type species: Schizotricha unifurcata Allman, 1883.

KEY TO SPECIES

1. Hydrotheca not completely adnate, one to each thecate internode. Stem unfascicled

S. simplex

— Hydrotheca completely adnate, more than one to each internode. Stem fascicled

S. frutescens

Schizotricha frutescens (Ellis & Solander, 1786)

Sertularia frutescens Ellis & Solander, 1786: 55, pl. 6 (figs a, A).

Schizotricha frutescens: Jaderholm, 1909: 108, pl. 12 (fig. 9). Vervoort, 1946a: 171, fig. 71.

Diagnosis. Stem fascicled, branching irregularly, reaching 200 mm, bearing

alternate hydrocladia in the distal regions. Axial tube in its distal region divided

into internodes each bearing one to three hydrothecae and one hydrocladium

from the side of each hydrotheca, alternately on the left and the right.

Hydrocladium consisting of thecate internodes separated by transverse

or slightly oblique nodes; each internode bearing one to five hydrothecae.

Hydrocladium normally branched, giving rise to a secondary branch from one

side of the first hydrotheca; the secondary branch sometimes rebranching in a

similar manner; secondary and tertiary branches similar to primary in structure.

No internodal septa. Three nematothecae corresponding to each hydrotheca,

one median inferior and one pair laterals.

Hydrotheca deep cup-shaped, completely adnate. Margin tilted slightly

towards internode.

Nematothecae all two-chambered and movable, with funnel-shaped distal

chamber. Median inferior seated well below hydrotheca and not reaching its

base. Lateral nematotheca overreaching thecal margin.

Male and female gonothecae (not reported from South Africa) borne on

different colonies, arising from below hydrothecae on the hydrocladia, (?female)

pear-shaped, with wide operculate distal aperture, bearing two nematothecae

near base.

Distribution outside South Africa. North Atlantic, Mediterranean, Kerguelen

Island. Type locality: Scarborough, U.K.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 369

Distribution in South Africa. One record only, by Krauss (1837) from Algoa

Bay. Needs confirmation. 33/25

Schizotricha simplex Warren, 1914

Fig. 118A-—C

Schizotricha simplex Warren, 1914: 83, figs 1-4, pl. 6.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 14

mm, consisting of an athecate basal part, and a distal thecate and hydrocladia-

bearing part, the two separated by two oblique hinge-joints. Basal part with a

variable number of transverse nodes. Distal part divided into thecate internodes

by oblique nodes. First thecate internode bearing a pair of opposite hydrocladia

arising from the sides of the hydrotheca; remaining hydrocladia alternate, one

to each internode. Three nematothecae to each internode, one median inferior

and one pair laterals.

Hydrocladium bearing hydrothecae on anterior surface, consisting of one

very short athecate and anematothecate internode terminated by a transverse

node and not always sharply demarcated from apophysis, then alternate athe-

cate and thecate internodes terminated by distinctly and slightly oblique nodes

respectively, usually two or three (rarely four) thecate internodes in all. Hydro-

cladium giving rise to a subsidiary branch from one side of the first hydrotheca.

Subsidiary branch similar to primary one in structure and forming an angle of

about 30° with it, bearing one or two hydrothecae. No internodal septa. Each

thecate internode with three nematothecae, one median inferior and one pair

laterals. Each athecate internode other than the first with one median

nematotheca.

Hydrotheca cup-shaped, with walls flaring slightly to margin, adnate for a

little over half height, with no intrathecal septum, 0,12—0,16 mm in abcauline

height, and 0,16-0,2 mm in marginal diameter. Margin forming an angle of

30—40° with internode.

Median inferior nematotheca not reaching base of hydrotheca, two-

chambered, probably movable, distal chamber scoop-shaped with low adcauline

wall. Lateral nematotheca borne on a short pedicel, not, or only just, reaching

thecal margin, two-chambered, movable, emarginated on both adcauline and

abcauline walls but more deeply on adcauline. Nematotheca of athecate inter-

node similar to median inferior.

Male and female gonothecae borne on same colony, the female on the

stem and the male on the first thecate internodes of the primary hydrocladia,

arising immediately below hydrothecae. Female gonotheca large, flattened

antero-posteriorly, pear-shaped in broad view, with wide distal operculate

aperture, with two large nematothecae on basal part, containing a single ovum

which develops into a planula in situ; pedicel of one segment. Male gonotheca

cylindrical or somewhat flattened, with bluntly pointed distal end.

Variation. Branching hydrocladia are found only in the older proximal part of

370 ANNALS OF THE SOUTH AFRICAN MUSEUM

a colony, and the last hydrocladia of a stem are usually unbranched.

Distribution. Endemic to South Africa. Type locality: near mouth of St. John’s

River, littoral.

Distribution in South Africa. Sparsely distributed from Still Bay to the Cape/

Natal border, littoral only. 34/21 (1), 34/22 (1), 33/27 (1), 31/29 (1)

Subfamily Kirchenpaueriinae

Diagnosis. Stem erect, branched or unbranched, fascicled or unfascicled,

giving rise to alternate hydrocladia. Hydrocladia arising from a single axial

tube in fascicled stems. No cauline hydrothecae. Hydrothecae small (usually

under 0,2 mm in depth). Nematothecae reduced: laterals absent; medians poorly

developed, seldom two-chambered, often rudimentary and sometimes repre-

sented by naked sarcostyles only. Gonothecae unprotected, not aggregated,

not bearing nematothecae.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Hydrothecal margin toothed Be ie aa Pe pea ic been

— Hydrothecal margin not toothed .. oe Sh ee : : ; Bae

2. Hydrotheca with abcauline intrathecal septum .. ae ae Pyenotheca jos 37 7/

— Hydrotheca without intrathecal septum .. a a, oe : 3

3. At least some of the hydrocladia forked .. - a ie \OspaIEEe p. .. 376

— No hydrocladia forked Be sit a: a oe .. Kirchenpaueria p. 370

Genus Kirchenpaueria Jickeli, 1883

Diagnosis. Stem branched or unbranched, bearing hydrocladia. Rarely with

simple forms where the hydrocladia arise directly from the hydrorhiza. Hydro-

cladia unbranched. Hydrotheca cup-shaped, without intrathecal septum, with

untoothed margin.

Type species: Sertularia pinnata Linnaeus, 1758.

KEY TO SPECIES

1. One median superior nematotheca present a ae oy eg ez

Median superior nematotheca replaced by a naked sarcostyle oe ss K. pinnata

2. Stem internode with at least one nematotheca on proximal region and one on

apophysis. eyes seated on proximal half of internode. Gonotheca triangular

in section aot K. triangulata

— Stem internode with one nematotheca in axil of hydrocladium, none on apophysis.

Hydrotheca seated on distal half of internode. Gonotheca round in section K. irregularis

Kirchenpaueria irregularis (Millard, 1958)

Fig. 118D-G

Plumularia irregularis. Millard, 1958: 211, fig. 13A—C.

Diagnosis. Hydrorhiza creeping. Stem fascicled at base, unbranched or

sparsely branched, reaching a height of 13 mm, bearing alternate hydrocladia,

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 371

Fig. 118.

Schizotricha s.. _-x. A, anterior view of stem with female gonophores; B, male gonotheca;

C, hydrocladium with branch. =

Kirchenpaueria irregularis. D and F, parts of hydrocladia; E, stem and origins of hydrocladia;

G, stem.

Scale: G in cm, the rest in mm/10.

372 ANNALS OF THE SOUTH AFRICAN MUSEUM

divided into regular internodes by transverse nodes. Each internode bearing

one hydrocladial apophysis near distal end, one mamelon on upper surface of

apophysis and one nematotheca immediately above apophysis. No internodal

septa. The two rows of hydrocladia in one plane.

Hydrocladium bearing hydrothecae on upper surface, very irregularly

segmented, normally consisting of only thecate internodes terminated by

transverse nodes, but often with intermediate athecate internodes. Each thecate

internode with two nematothecae, one median inferior not reaching base of

hydrotheca and one median superior. No internodal septa. Hydrotheca seated

on distal half of internode.

Hydrotheca cup-shaped, not completely adnate, widening to margin,

0,07-0,11 mm in abcauline depth and 0,10-0,12 mm in marginal diameter.

Margin oblique. |

Nematotheca two-chambered, with very small basal chamber, flask-shaped,

with convex abcauline wall.

Gonothecae unknown.

Variation. The hydrocladial internodes vary greatly in length though generally

very long and slender. Athecate internodes may occur in almost any position

on the hydrocladia, as many as three at the base and up to two between conse-

cutive thecate internodes. Usually these are bounded by straight nodes and

carry no nematothecae. Occasionally, however, the distal part of a thecate

internode is cut off behind the hydrotheca by an oblique node, carrying with it

the median superior nematotheca.

The hydrothecae are adnate for about +-%. Those with an oblique node

behind them have a long free portion.

Distribution. Endemic to Southern Africa.

Distribution in South Africa. Natal and Mocambique, rare; type locality:

Salisbury Island, Durban Bay. 29/31 (1), 21/35

Kirchenpaueria pinnata (Linnaeus, 1758)

Fig. 119A-D

Sertularia pinnata Linnaeus, 1758: 813.

Plumularia pinnata: Hincks, 1868: 295, pl. 65 (fig. 1). Ritchie, 19075: 541.

?Plumularia Gaymardi: Kirchenpauer, 1876: 27, pl. 1 (fig. 6), pl. 3 (fig. 6).

Plumularia echinulata: Ritchie, 1907b: 540. Ritchie, 1909: 87.

Plumularia unilateralis Ritchie, 1907b: 541, pl. 2 (fig. 1).

Kirchenpaueria pinnata: Vervoort, 19466: 321. Millard, 1957: 233.

Diagnosis. Hydrorhiza creeping. Stem unfascicled, unbranched, usually reaching

a height of 10-30 mm (maximum 75 mm), bearing alternate hydrocladia, divided

into internodes by transverse or slightly oblique nodes. Each internode bearing

a variable number of hydrocladia on short apophyses and two naked sarco-

styles in the axil of each, one on upper surface of apophysis and one on stem

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 373

just above apophysis. No internodal septa. No mamelon. The two rows of

hydrocladia in one plane or displaced towards the anterior surface.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

very short athecate and anematothecate internode, then all thecate internodes

terminated by oblique nodes. Each thecate internode with one median inferior

nematotheca and one median superior ‘naked sarcostyle. Internodal septa

absent, or two in each thecate internode, one proximal and one distal, and one

in the athecate internode. Hydrotheca seated in centre of internode.

Hydrotheca cup-shaped, almost completely adnate (3-4), with straight

abcauline wall, 0,07—0,12 mm in abcauline depth and 0,12—0,17 mm in marginal

diameter. Margin oblique, reaching approximately to next node.

Median inferior nematotheca minute, scoop-shaped, one-chambered, with

no adcauline wall. All others reduced to naked sarcostyles emerging through

foramina in the perisarc.

Gonothecae borne on stem (but not on the hydrocladial apophyses) or

hydrorhiza, without nematothecae, elongate-oval, with longitudinal ridges

which often bear spines.

Variation. This is a very variable species, in which features such as the number

of hydrocladia to a stem internode, presence or absence of athecate internodes

in the hydrocladia, shape of hydrotheca and presence or absence of spines on

the gonotheca have been used in the past for the separation of species, varieties

or forms. South African material conforms most nearly to the typical form as

described by Hincks.

The length of the stem internodes varies, and each may bear one to four

hydrocladia, depending on the length. The most common number is two, with

a tendency for more near the base and only one near the tip. In some stems all

internodes bear one hydrocladium each.

The hydrocladia lack regular athecate internodes (other than the first).

Occasional ones do, however, occur sporadically, with 0, 1, or 2 median

nematothecae each.

Ritchie (19075) has reported a colony from Saldanha Bay (as Plumularia

unilateralis) with branching hydrocladia, but no further examples have been

seen. Rare examples of solitary hydrocladia arising separately from the

hydrorhiza occur.

Gonothecae vary in the development of the spinous processes. In general,

young ones are practically smooth, older ones ribbed longitudinally, and fully

mature ones provided with spines. Female gonothecae appear to be more

spinous than male.

Distribution. Cosmopolitan. Type locality: U.K.

Distribution in South Africa. From South West Africa on the west to Natal on

the east; the most common littoral hydroid in the south-western Cape; also

common on ships’ hulls and in shallow water, extending down to 64 m. 22/14,

374 ANNALS OF THE SOUTH AFRICAN MUSEUM

——————

Pics iS:

Kirchenpaueria pinnata. A, hydrocladium; B, part of stem with origins of hydrocladia;

C, fertile stems; D, gonothecae, arising from hydrorhiza.

Kirchenpaueria triangulata. E, colony with pinnate stem bearing gonothecae and several simple

stems; F, nematotheca; G, part of stem showing nematothecae and origins of hydro-

cladia; H, hydrocladium.

Scale: C in cm, E in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 375

29/16 (1), 33/17 (s), 33/18 (h, 1, s), 34/18 (1, s), 34/21 (1), 34/22 (1), 34/23 (h, 1. s),

33/25 (1, s), 34/25 (s), 33/27 (1), 32/28 (1), 31/29 (1), 31/30 (1), 29/31 (s)

Kirchenpaueria triangulata (Totton, 1930)

Fig. 119E-H

Plumularia triangulata Totton, 1930: 225, fig. 61. Ralph, 1961: 41, fig. 5f-g.

Kirchenpaueria triangulata: Millard, 1962: 292, fig. 6E-J. Vervoort, 19665: 136, figs 38-39.

Millard, 1967: 184.

Diagnosis. Hydrorhiza creeping, giving rise to both pinnate stems and, as a

secondary growth-form, separate hydrocladia. Pinnate stem unfascicled,

unbranched, reaching 10-35 mm in height, bearing alternate hydrocladia,

divided into regular internodes by straight nodes which may be indistinct in

parts. Each internode bearing one hydrocladial apophysis at distal end, one

mamelon on upper surface of apophysis and two to four nematothecae, includ-

ing one on proximal end immediately above last apophysis and one on upper

surface of apophysis distal to mamelon. No internodal septa. The two rows of

hydrocladia in one plane or displaced slightly to the anterior surface.

Hydrocladium bearing hydrothecae on upper surface, consisting of thecate

internodes only, terminated by straight or slightly oblique nodes. Each internode

with two nematothecae, one median inferior and one median superior. No

internodal septa. Hydrotheca seated in proximal half of internode.

Separate hydrocladium borne on long apophysis of hydrohiza, about

4 mm in height, exactly similar to those borne on the stem except that the

measurements of individual parts are slightly less.

Hydrotheca cup-shaped, completely adnate or with a very short free part,

widening slightly to margin, 0,07—0,10 mm in abcauline depth and 0,10—0,12 mm

in marginal diameter. Margin slightly oblique and very slightly everted.

Nematotheca one-chambered, movable, flask-shaped, with convex

abcauline wall and practically straight adcauline wall.

Gonothecae borne on hydrocladial apophyses of stem, large (reaching

3 mm in length), without nematothecae, increasing in diameter to truncated

distal end, triangular in section, with short pedicel of two segments.

Variation. In South Africa this species grows epizootically on other hydroids.

In pinnate stems there is a tendency for the nodes to be indistinct or com-

pletely absent. This is most common in the proximal part and sometimes only

the last few nodes are visible. Occasionally the node between the hydrocladial

apophysis and the first thecate internode is also indistinct.

Athecate internodes of variable length (possibly due to regeneration)

commonly occur in the hydrocladia. They may be present in any position, but

are most common at the proximal ends.

Although the nematothecae are one-chambered a very thin septum is

sometimes visible near the base. The number of cauline nematothecae is variable,

although the two mentioned in the diagnosis always occur.

376 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. New Zealand. Type locality: off Three

King’s Island in 550 m.

Distribution in South Africa. A deep-water species occurring at scattered

localities from off the Cape Peninsula to Mocgambique in 111-1 207 m. 34/17 (d),

34/23 (d), 29/31 (d), 28/32 (a), 25/35 (vd)

Genus Oswaldella Stechow, 1919

Diagnosis. Stem unfascicled, unbranched or sparingly branched, bearing hydro-

cladia. Rarely with a simple form where the hydrocladia arise direct from the

hydrorhiza. At least some of the hydrocladia forking once or several times in a

plane at right angles to the hydrocladium. Hydrotheca cup- or jug-shaped,

without intrathecal septum, with untoothed margin.

Type species: Schizotricha bifurca Hartlaub, 1904.

One species in South Africa.

Oswaldella nova (Jarvis, 1922)

Fig. 120A—C

Plumularia nova Jarvis, 1922: 347, pl. 26 (fig. 20).

Kirchenpaueria adhaerens Millard, 1958: 203, fig. 13 F—G.

Oswaldella nova: Millard, 1962: 295, fig. 6A—D. Millard, 1973: 28, fig. 5.

Diagnosis. Hydrorhiza epizootic on other hydroids (Plumulariidae, Halopteri-

nae), giving rise, so far as is known, to simple stems (hydrocladia) only.

Hydrocladia borne on long apophyses of hydrorhiza, reaching a maximum

height of 7 mm, often forked dichotomously once or twice. The two limbs of a

fork of equal length and thickness and bearing hydrothecae on the same surface

as the undivided part. Hydrocladium consisting of thecate internodes only,

terminated by oblique nodes. Each internode with one median inferior nemato-

theca and one median superior naked sarcostyle situated behind adcauline

wall of hydrotheca. One median nematotheca on apophysis of hydrorhiza. No

internodal septa. Hydrotheca seated approximately in centre of internode.

Hydrotheca cup-shaped, either completely adnate or with a very short

free part, with straight or slightly concave abcauline wall, 0,05-0,12 mm in

abcauline depth and 0,07-0,14 mm in marginal diameter. Hydranth with about

16 tentacles.

Median inferior nematotheca minute, one-chambered, saucer-shaped,

often missing.

Male gonothecae borne singly immediately below hydrothecae, elongated,

with truncated distal end and curved base, reaching 0,90 mm in length and

0,27 mm in maximum diameter. Female gonothecae unknown.

Variation. The hydrocladia may be undivided and very short, bearing only two

or three hydrothecae. At the other extreme are long hydrocladia forked twice,

reaching 7 mm and bearing up to 15 hydrothecae. The hydrorhizal apophysis

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA S77

may be separated off by a node, and the distal end of an internode may be

separated off by a straight node to form an athecate intermediate internode.

Internodes of very variable length.

Remarks. It is possible that this is a stunted epizootic form of a species with a

pinnate stem such as O. bifurca (Hartlaub, 1904) or O. antarctica (Jaderholm,

1904). Both the latter are antarctic forms.

Distribution outside South Africa. Tropical East Africa. Type locality: Zanzibar.

Distribution in South Africa. From the west coast of the Cape Peninsula to

Mocambique in 10-110 m. 34/18 (s), 35/21 (d), 34/22 (s), 34/23 (s), 33/26 (s),

33/27 (s), 30/30 (s), 28/32 (s), 21/35

Genus Pycnotheca Stechow, 1919

Syn. Diplocheilus Allman, 1883.

Diagnosis. Stem unbranched or sparsely branched, bearing hydrocladia.

Hydrocladia unbranched. Hydrotheca cup-shaped, with strong abcauline

intrathecal septum and untoothed margin.

Type species: Diplocheilus mirabilis Allman, 1883.

One species only in South Africa.

Pycnotheca mirabilis (Allman, 1883)

Fig. 120D-G

Diplocheilus mirabilis Allman, 1883: 49, pl. 8 (figs 4-7). Stechow, 1913: 88, figs 55—56.

Kirchenpaueria mirabilis: Warren, 1908: 321, fig. 15. Stechow, 19255: 241.

Pycnotheca mirabilis: Totton, 1930: 216, fig. 55a—d. Millard, 1957: 234. Ralph, 19615: 50,

fig. 7a—b. .

Diagnosis. Hydrorhiza creeping. Stem unfascicled, unbranched, reaching 30 mm

in height, bearing alternate hydrocladia, divided into internodes by very oblique

nodes which are successively more distinct towards the base where they resemble

hinge-joints. Each internode bearing one or two hydrocladial apophyses, the

two rows of hydrocladia not in one plane but displaced onto anterior surface.

No internodal septa. Mamelon present on upper surface of apophysis. One

nemathotheca on each hydrocladial apophysis and one on the anterior surface

of the distal end of each stem internode.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes only, terminated by oblique nodes. Each internode with one

median inferior nematotheca close below base of hydrotheca and one median

superior naked sarcostyle behind adcauline wall of hydrotheca. Internodes

short and hydrothecae close-set, with margin of one almost reaching the base

of the next. No internodal septa. Hydrotheca seated in centre of internode.

Hydrotheca cup-shaped, widening slightly to a circular aperture, adnate

for about two-thirds height, with strong abcauline intrathecal septum reaching

about half-way across cavity and triangular in side view, 0,2-0,3 mm in depth

378 ANNALS OF THE SOUTH AFRICAN MUSEUM

E F

Fig. 120.

Oswaldella nova. A, epizootic colony on Halopteris glutinosa (hydrocladia of host cut off

short); B, hydrocladium; C, hydrocladium with male gonothecae.

Pycnotheca mirabilis. D, fertile colony; E, anterior view of stem showing origins of

hydrocladia; F, hydrocladium; G, gonotheca.

Scale: D in cm, A in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 379

and 0,18-0,3 mm in marginal diameter. Margin oblique. Hydranth with about

18 tentacles.

Median inferior and cauline nematothecae scoop-shaped, one-chambered,

immovable, with no adcauline wall. Median superior naked sarcostyle seated

in a funnel-shaped depression of the perisarc.

Gonothecae borne on hydrorhiza or on basal part of stem replacing

hydrocladia, without nematothecae, elongate-oval, transversely annulated,

with truncated distal end, containing one or two gonophores.

Variation. Minor differences in structure have led to the establishment of

separate varieties, geographical races or subspecies (Stechow 19254; Totton

1930). The features used include the thickness of the stem and hydrocladia,

the number of hydrocladia to a stem internode (one or two), the size of the

hydrotheca, the distance between consecutive hydrothecae, the thickness of the

intrathecal septum, the proportion of the free part of the adcauline thecal wall

and the plane of the basal opening of the median inferior nematotheca. In

general there seems little justification for subdivision of the species. In South

African material the longer stem internodes near the base tend to bear two hydro-

cladia, the shorter ones near the tip one. The measurements of the False Bay

material are on the whole greater than those of the east coast material.

Distribution outside South Africa. South-east Madagascar, Australia, New

Zealand, Japan, India, Pacific coast of North America, Vema Seamount (South

Atlantic). Type locality: Bass Strait in 69-73 m.

Distribution in South Africa. False Bay and the coasts of Natal and Mocambique,

littoral to 49 m. 34/18 (s), 30/30 (1, s), 29/31 (s), 28/32 (s), 26/32 (1, s)

Subfamily Plumulariinae

Diagnosis. Stem erect, branched or unoranched, fascicled or unfascicled, giving

rise to hydrocladia alternately or in alternating verticils. Hydrocladia arising

from a single axial tube in fascicled stems. No cauline hydrothecae. Hydro-

thecae small (usually under 0,2 mm in depth). Nematothecae generally two-

chambered and movable, not fused to hydrotheca, at least three associated with

every hydrotheca (one median inferior and one pair laterals). Gonothecae

unprotected, not aggregated, generally without nematothecae.

KEY TO GENERA

1. Mature stem and branches bearing verticils of hydrocladia, those of one verticil

normally alternating with those above and below forming double the number of

longitudinal rows oi = oe de a ws . Nemertesia p. 381

— Stem and branches bearing alternate hydrocladia which form two longitudinal rows .. 2

2. Hydrotheca with untoothed margin ee aye Ee : Plumularia p. 388

— Hydrotheca with toothed margin .. at ef aS Aa Dentitheca p. 380

380 ANNALS OF THE SOUTH AFRICAN MUSEUM

Genus Dentitheca Stechow, 1919

Diagnosis. Stem pinnate, giving rise to alternate hydrocladia. Hydrotheca

cylindrical to cup-shaped, margin with a large lobe on each side.

Type species: Plumularia hertwigi Stechow, 1909

One species only from South Africa.

Dentitheca bidentata (Jaderholm, 1920)

Fig. 121A—C

Plumularia bidentata Jaderholm, 1920: 7, pl. 2 (figs 5-6).

Plumularia crosslandi Jarvis, 1922: 346, pl. 25 (fig. 18).

Dentitheca crosslandi: Vannucci, 1949: 250, pl. 3 (figs 49-50).

Dentitheca bidentata: Millard & Bouillon, 1973: 78, fig. 11C.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 32

mm, bearing alternate hydrocladia, divided into internodes by oblique nodes,

those near the base forming hinge-joints. Each internode bearing a variable

number of hydrocladia. Three nematothecae to each apophysis (one on apophy-

sis, one in axil, one on stem next to origin), one on anterior surface of base of

internode and sometimes one on distal end of internode. Mamelon present on

upper surface of apophysis. The two rows of hydrocladia not in the same plane

but displaced towards the anterior surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by oblique nodes and bearing the hydrotheca on

the basal half. Each internode with one long median inferior nematotheca

reaching about half-way up length of hydrotheca, one pair shorter laterals not

reaching level of lateral thecal teeth and one median superior. Up to six peri-

sarcal thickenings on anterior surface which may be developed as internodal

septa.

Hydrotheca completely adnate, with the perisarc usually strongly thickened

and projecting into the interior near the distal end of the abcauline side and

sometimes the adcauline side as well. Margin with two large, triangular lateral

lobes and an abcauline lobe which is bent out at an angle to the axis. Hydro-

theca 0,10-0,13 mm in abcauline height and 0,07-0,14 mm in marginal diameter.

Nematothecae all two-chambered and movable, the median inferior with

an extra long basal chamber.

Gonothecae (not reported from South Africa) arising from axils of hydro-

cladia, cylindrical, with two longitudinal ridges on anterior surface and four

irregular distal expansions (Jarvis).

Variation. The structure of the lower part of the stem is variable and as many

as five of the basal nodes may be in the form of hinge-joints. One stem was seen

with four branches. The number of hydrocladia to an internode varies from

one to four.

The perisarc of the hydrotheca varies in thickness. In young hydrothecae

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 38]

the abcauline wall is only slightly thickened. In older ones this thickening pro-

jects into the cavity as a large triangular tooth and there is a second smaller

projection into the cavity from the adcauline wall.

Distribution outside South Africa. Brazil (type locality: south of Pernambuco,

9°S, 33 m); tropical western Indian Ocean: Wasin, Madagascar, Seychelles.

Distribution in South Africa. Durban to Inhaca, littoral to 48 m. 28/32 (s),

26/32 (1)

Genus Nemertesia Lamouroux, 1812

Syn. Antennularia Lamarck, 1816.

Diagnosis. Hydrocladia arranged in verticils in mature colonies, the number

to a verticil typically increasing with age, and members of one verticil typically

alternating with those above and below forming double the number of

longitudinal rows. Hydrotheca cup-shaped, with untoothed margin.

Type species: Sertularia antennina Linnaeus, 1758.

KEY TO SPECIES

1. All hydrocladial internodes normally thecate sti he ae .. NN. ramosa

— Hydrocladial internodes alternately thecate and athecate oe ev? an Pe

2. Stem unbranched and unfascicled .. if Se re ot oe N. antennina

— Stem branched and fascicled a af A os us w Gus ee Lo

3. Branching in one plane, stiff. Each stem internode bearing more than one whorl of

hydrocladia. First hydrocladial internode thecate : .. N. ciliata

— Branching irregular, flexuous. Each stem internode bearing only one whorl of hydro-

cladia. First hydrocladial internode athecate or ue Fe ae N. cymodocea

Nemertesia antennina (Linnaeus, 1758)

Fig. 121D-E

Sertularia antennina Linnaeus, 1758: 811.

Antennularia irregularis Quelch, 1885: 8, pl. 2 (fig. 4).

Antennularia antennina: Billard, 1904a: 211, figs 80-86. Hincks, 1868: 280, pl. 61.

Nemertesia antennina: Stechow, 1912: 365. Vervoort, 1946a: 179, figs 74a, 75, 76a.

Nemertesia antennina irregularis: Vervoort, 19666: 140, fig. 42.

Diagnosis. Stems thread-like, unfascicled, unbranched or rarely with one or

two branches, reaching 55 mm. Hydrocladia borne in whorls of 2-10. Stem

divided by transverse nodes (which may be obscure) into internodes each

bearing one whorl of hydrocladia. Mamelon present on upper surface of hydro-

cladial apophysis. A variable number of nematothecae corresponding to each

apophysis but always one pair in axil.

Hydrocladium consisting of alternate short athecate and long thecate

internodes. Athecate internodes with one or two median nematothecae. Thecate

internodes with three nematothecae, one median inferior and one pair laterals

overreaching thecal margin.

382 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 121.

Dentitheca bidentata. A, hydrocladium; B, part of stem in lower region showing origin of

hydrocladium; C, stems.

Nemertesia antennina, redrawn from Vervoort (1966). D, gonotheca; E, hydrocladium.

Nemertesia ciliata. F, hydrocladium from old region of stem; G, more typical hydrocladium;

H, stem; J and K, parts of stem with two and three hydrocladia per whorl respectively,

J with gonothecae (nematothecae omitted).

Scale: C and H in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 383

Hydrotheca cup-shaped, completely adnate, widening to margin, 0,07 mm

in abcauline depth and 0,08-0,09 mm in marginal diameter.

Nematothecae all two-chambered and movable.

Gonothecae borne on hydrocladial apophyses, without nematothecae,

smooth, pear-shaped, with wide, oblique aperture tilted towards stem. Male

and female similar, on same colony. Female containing one egg, rarely two,

which develops into a planula in situ.

Variation and remarks. The general appearance of this species with its

unbranched, thread-like stems is very characteristic. It is recognized as being

extremely variable in structure and several varieties and/or subspecies have been

described. Variations involve:

(i) The number of hydrocladia to a whorl, which probably increases with age.

(ii) The presence or absence of nodes on the stem.

(iii) The segmentation of the hydrocladia, where extra intermediate athecate

internodes may occur.

(iv) The number of nematothecae to an athecate internode. One appears to be

normal, but two may occur or, on extra intermediate internodes, none at all.

Stechow (1912) reports the species from South Africa without locality

or depth. Since his material was dry, without hydrocladia and without

gonothecae, this record is subject to doubt.

Vervoort (19665) reports subspecies irregularis from off Durban, and the

measurements given above are from this work. Vervoort reports that the whorls

of hydrocladia do not alternate as is usual for the species.

Because of the variability within the species, and because it is so poorly

known in South Africa, I prefer not to be categorical about subdivision into

subspecies and/or varieties. There is also a possibility of confusion with young

colonies of NV. cymodocea.

Distribution outside South Africa. Atlantic Ocean from Greenland to tropical

West Africa and from North America to Europe. Mediterranean. Pacific.

Type locality: U.K.

Distribution in South Africa. Off Durban in 425-430 m. 29/31 (d)

Nemertesia ciliata Bale, 1914

Fig. 121 F—K

Nemertesia ciliata Bale 19145: 170, pl. 36 (fig. 1). Briggs, 1915: 307, pl. 10 (fig. 3). Bale, 1915:

298. Jaderholm, 1919: 23. Millard, 1962: 297, fig. 7E-G.

Nemertesia ciliata var. cruciata Bale, 1915: 300.

Diagnosis. Hydrorhiza matted and thick. Stem thick and fascicled, reaching

245 mm, branching and rebranching in an irregularly alternate fashion and

always in one plane. Branches forming an acute angle with stem, larger ones

fascicled, smaller ones unfascicled. Hydrocladia borne in whorls of 2-4 on long

apophyses of stem and branches, the whole often compressed in one plane.

Axial tube of stem and branches, where exposed, with irregular transverse

384 ANNALS OF THE SOUTH AFRICAN MUSEUM

nodes, usually after every two or three whorls of hydrocladia. Mamelon pre-

sent on upper surface of hydrocladial apophysis. Three or four nematothecae

corresponding to each apophysis, two in the axil and one or two medians on

upper surface distal to the mamelon, none on main axial tube. Scattered

nematothecae on peripheral tubes.

Hydrocladium bearing hydrothecae on upper surface, consisting of alternate

long thecate and short athecate internodes separated by oblique nodes. All

internodes with at least two internodal septa, one proximal and one distal.

Athecate internodes with one median nematotheca on proximal end. Thecate

internodes with three nematothecae, one median inferior on proximal end and

well below base of hydrotheca and one pair laterals overreaching thecal margin.

Hydrotheca seated approximately in centre of internode.

Hydrotheca cup-shaped, completely adnate, widening to margin, 0,02—

0,07 mm in abcauline depth and 0,06-0,09 mm in marginal diameter. Margin

perpendicular to hydrocladium.

Nematothecae all two-chambered and movable. Distal chamber funnel-

shaped, deeply emarginated on adcauline side in medians, slightly so in laterals.

Gonothecae borne on hydrocladial apophyses, without nematothecae,

smooth, often curved, widening from base to truncated distal end, with broad

terminal aperture.

Variation. As is usual in this genus there is variation in the number of hydro-

cladia to a whorl. At the base of a stem or branch the arrangement is either

alternate or quite irregular. Further up there is a rough grouping into whorls,

though the members of a whorl are not all at the same level, until finally the

regular whorls are established.

Distribution outside South Africa. Tasmania, Japan. Type locality: Oyster Bay,

Tasmania.

Distribution in South Africa. From the west coast to off Port Elizabeth in 11—

392 m. 31/16 (d), 34/17 (d), 34/18 (d), 35/21 (d), 26/21 (d), 34/22 (s), 34/23 (d),

34/25 (s)

Nemertesia cymodocea (Busk, 1851)

Fig. 122A-C

Antennularia Cymodocea Busk, 1851: 119.

Nee (Antennularia) decussata Kirchenpauer, 1876: 52, 54, pl. 2 (fig. 24), pl. 3 (fig. 24),

pl. 7 (fig. 24).

?Nemertesia (Antennularia) Johnstoni Kirchenpauer, 1876: 52, 54, pl. 8 (fig. 26).

Antennularia decussata: Marktanner-Turneretscher, 1890: 258, pl. 6 (fig. 7).

Antennularia hartlaubi Ritchie, 1907b: 542, pl. 3 (fig. 4).

Nemertesia cymodocea: Billard, 1910: 39. Millard, 1957: 234. Millard, 1961: 207. Ralph,

1961b: 49, fig. 6k. Millard, 1962: 299.

Diagnosis. Hydrorhiza matted and spreading. Stem thick and fascicled, reaching

100 mm or more (maximum 492 mm), dividing irregularly and usually close to

the base into long flexuous branches, which may be fascicled in basal region.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 385

Hydrocladia in whorls of two or three. Branches divided into regular internodes

by transverse nodes, each internode bearing two or three hydrocladial apophyses

near distal end. Mamelon present on upper surface of apophysis. Nemato-

thecae present on peripheral tubes of fascicled stem. Three nematothecae cor-

responding to each apophysis, two seated side by side on its upper surface and

one on the next internode immediately above it.

Hydrocladium bearing hydrothecae on upper surface, consisting of alternate

short athecate and long thecate internodes separated by slightly oblique nodes.

All internodes with at least two internodal septa, one proximal and one distal.

Athecate internodes with one median nematotheca. Thecate internodes with

three nematothecae, one median inferior reaching approximately to base of

hydrotheca and one pair laterals overreaching thecal margin. Hydrotheca

seated approximately in centre of internode.

Hydrotheca cup-shaped, completely adnate, widening to margin, 0,06-0,11

mm in abcauline depth and 0,08-0,14 mm in marginal diameter. Margin perpen-

dicular or slightly oblique to hydrocladium.

Nematothecae all two-chambered and movable; distal chamber funnel-

shaped and with adcauline wall lower than abcauline.

Gonothecae borne on hydrocladial apophyses, without nematothecae,

smooth, compressed, flask-shaped and often slightly curved in side view, with

terminal aperture on a short tubular neck, held parallel to branch.

Variation. The most obvious variation is in the number of hydrocladia to a

whorl, two (decussate arrangement) and three (hexastichous arrangement)

being the most common, but there may also be only one (alternate arrange-

ment) and Kirchenpauer (1876) reports four. It appears that generally, though

possibly not always, this is a factor of age, for very young colonies have alternate

hydrocladia and develop the decussate arrangement only at the tips of the

branches; mature colonies have normally lost the hydrocladia in the older

fascicled part of the stem and have the decussate arrangement in the proximal

regions of the branches and the hexastichous arrangement more distally. Some

colonies are entirely decussate and some entirely hexastichous.

Occasionally a secondary hydrocladium arises from the apophysis of the

primary. This is not a regular occurrence and appears to be an abnormal

condition in which the secondary hydrocladium replaces a gonophore.

The number and strength of the internodal septa in the thecate internodes

is also variable, and in addition to the basic two (proximal and distal) there

may be one opposite the base of the hydrotheca, another immediately above

this and another below it.

Other minor variations include the presence of extra athecate regeneration

internodes, of which there may be as many as six at the base of the

hydrocladium, and the presence of an extra nematotheca on the hydrocladial

apophysis.

Distribution outside South Africa. New Zealand, south-western Atlantic.

386 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. From Saldanha Bay to East London in 5-170 m.

Type locality: ‘South Africa’. 33/17 (s), 33/18 (s), 34/18 (s), 34/19 (s), 34/20 (s),

35/21 (d), 34/22 (s),--35/22 ), 34/23 (s, d), 33/25 (s), 34/25 (sd); 33 26K

33/27 (s), 32/28 (s)

Nemertesia ramosa Lamouroux, 1816

Fig. 122D-H

Nemertesia ramosa Lamouroux, 1816: 164. Millard, 1957: 235. Millard, 1962: 299, fig. 7A—D.

Vervoort, 19665: 139, fig. 41. Redier, 1967: 395. Vervoort, 1972: 234, fig. 83.

Antennularia ramosa: Hincks, 1868: 282, pl. 62.

Diagnosis. Hydrorhiza thick and matted. Stem thick and fascicled, generally

reaching 40-160 mm (maximum 282 mm), unbranched or branching irregularly,

bearing hydrocladia in whorls of two to five. Nodes either absent altogether or

transverse and quite irregular. Hydrocladial apophyses stout, bearing a mamelon

on upper surface. Four to seven nematothecae corresponding to each apophysis,

one or two on stem above apophysis, one pair on the apophysis in the axil and

one to three distal to mamelon.

Hydrocladia bearing hydrothecae on upper surface, normally consisting of

only thecate internodes separated by slightly oblique nodes. Internodal septa

present or absent. Each internode with three or four nematothecae, one median

inferior not reaching base of hydrotheca, one pair laterals overreaching thecal

margin and generally one median superior. Hydrotheca seated in proximal half

of internode.

Hydrotheca cup-shaped, completely adnate, widening to margin, 0,06-0,14

mm in abcauline depth and 0,07-0,14 mm in marginal diameter. Margin

perpendicular or slightly oblique to hydrocladium.

Nematothecae all two-chambered and movable; distal chamber

funnel-shaped with adcauline wall slightly lower than abcauline.

Gonothecae borne on hydrocladial apophyses, without nematothecae,

smooth. Male elongate-oval, symmetrical and with rounded distal end when

young, slightly curved and with oblique aperture when mature. Female curved,

widening to distal end, with broad oblique aperture usually facing towards

stem. Eggs developing into planulae in situ.

Variation. This is an extremely variable species, both in the arrangement of

hydrocladia and in the segmentation within them.

In young stems the hydrocladia are alternate, but as development proceeds

whorls of two, three, four, five, or even six are produced, with the result that

whorls with a larger number of hydrocladia occur at the distal end of the stem.

In time the lower (alternate) hydrocladia fall off or are obscured by the

fasciculation. Sometimes the arrangement is quite irregular in parts.

Though the normal condition seems to be hydrocladia with only thecate

internodes, athecate internodes may occur either below the first thecate one or

between any two thecate ones. This, however, is not a regular occurrence as in

N. cymodocea.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 387

ig. 122.

Nemertesia cymodocea. A, stem; B, part of stem with three hydrocladia per whorl and female

gonothecae (nematothecae omitted); C, hydrocladium.

Nemertesia ramosa. D, part of stem with three hydrocladia per whorl and female gonothecae

(nematothecae omitted); E, typical hydrocladium with no median superior nematotheca;

F, hydrocladium with small hydrothecae and with median superior nematothecae;

G, hydrocladium from old stem and with median superior nematothecae; H, stem.

Scale: A and H in cm, the rest in mm/10.

388 ANNALS OF THE SOUTH AFRICAN MUSEUM

In the hydrocladial internodes septa commonly occur, including one at the

proximal end and one at the distal end, the number increasing with age, so

that in old colonies as many as 12 may be present.

The median superior nematotheca is not invariably present in the thecate

internodes. It is sometimes absent altogether, or may be cut off on an athecate

internode.

Variation also occurs in the gonothecae. Female gonothecae normally have

the aperture facing towards the stem, but examples have been seen where the

gonothecae, containing embryos, are quite symmetrical and with terminal

apertures.

Distribution. Cosmopolitan. Type locality: “European Ocean’. Syntype from

Dieppe and Calvados (Redier 1967).

Distribution in South Africa. From off Table Bay, round the south coast and up

the east coast to Mocgambique, in 11-700 m. 33/18 (s), 34/18 (s), 35/21 (d),

34/22 (s), 35/22 (d), 34/23 (d), 33/25, 34/25 (s, d), 30/31 (d), 29/31 (d, vd),

27/32 (d), 25/35 (vd), 24/35 (d)

Genus Plumularia Lamarck, 1815

Diagnosis. Stem branched or unbranched (always unbranched in South Africa),

bearing hydrocladia. Rarely with simple forms where the hydrocladia arise

directly from the hydrorhiza. Hydrocladia alternate, sometimes with the whole

plume spirally twisted (though not in South Africa), unbranched.

Type species: Sertularia setacea Linnaeus, 1758

KEY TO SPECIES

1. Hydrocladium bearing one hydrotheca only a a: Se a me Ze ee

— Hydrocladium bearing more than one hydrotheca ae A 3 oe oe

2. Hydrotheca with adcauline intrathecal septum. Hydrocladium enter in spine P. spinulosa

— Hydrotheca without intrathecal septum. Hydrocladium broadly rounded distally .. 3

3. Hydrotheca with concave abcauline wall. Two nematothecae in axil of hydro-

cladium Es ae P. pulchella

— Hydrotheca with convex to straight abcauline pall One nematotheca in axil of

hydrocladium aes : a ne .. P. obliqua

4. Hydrotheca adnate for half or ieee of eacauline het a ae a ies

— Hydrotheca completely adnate or practically so uae Re ire ee

5. Hydrotheca with adcauline intrathecal septum. Gonotheca flat on substrata P. filicaulis

— Hydrotheca without intrathecal septum. Gonotheca borne on stem .. Bs Be lO

6. Each stem internode with three nematothecae, two in axil of hydrocladium and one

on opposite surface. Hydrotheca with free part of adcauline wall concave P. pennycuikae

Stem with numerous nematothecae in two longitudinal rows. Hydrotheca with free

part of adcauline wall straight .. a 1 ae a - .. P. wasini

7. Abcauline wall of hydrotheca markedly convex * eh rs P Bee

— Abcauline wall of hydrotheca more or less straight 8

8. One nematotheca on each hydrocladial apophysis. Hydrotheca sited more or vleen in

centre of internode 3

— Two nematothecae on each hydrocladial apophysis. Hydrotheca usually not: in n centre

of internode ah iy, es ty: ee a: we is As Bo Lil

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 389

9. Gonotheca transversely annulated, borne on base of stem only P. strictocarpa

— Gonotheca smooth, borne at any level on stem oe ea ree of aa 2D

10. Female gonotheca with external marsupium, without neck .. ~ .. P. warreni

— Female gonotheca without marsupium, with curved tubular neck .. .. P. setacea

11. Athecate internodes, when present, cut off from proximal end of thecate internodes,

when not present hydrotheca seated on distal half of internode. First hydrocladial

internode very short (less than 4 normal thecate internode) .. ave P. antonbruuni

— Athecate internodes, when present, cut off from distal end of thecate internodes,

when not present hydrotheca seated on proximal half of internode. First hydrocladial

internode not very short (about 4 normal thecate internode) .. .. P. mossambicae

Plumularia antonbruuni Millard, 1967

Fig. 123A-D

Plumularia antonbruuni Millard, 1967: 185, fig. 5.

Diagnosis. Hydrorhiza penetrating into soft substratum, branching and fila-

mentous. Stem unfascicled, reaching 51 mm, bearing alternate hydrocladia,

indistinctly divided into internodes in upper region only, by straight nodes.

Where demarcated each internode bearing one hydrocladial apophysis in distal

half and three nematothecae, one on opposite side to apophysis and two on

apophysis. No internodal septa. Mamelon present on upper surface of apophysis.

The two rows of hydrocladia in one plane.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

very short athecate internode, then either all long thecate internodes or alter-

nate athecate and thecate internodes, the latter condition being more common

towards the distal end and the athecate internodes being cut off from the

proximal ends of the thecate internodes. Nodes slightly oblique. First internode

without nematothecae, with one internodal septum. Other athecate internodes

with 0-2 median nematothecae and two internodal septa, one proximal and one

distal. Thecate internodes with 0-3 median inferior nematothecae, the upper-

most not reaching base of hydrotheca, one pair laterals overreaching thecal

margin and sometimes one median superior; with two internodal septa, one

proximal and one distal. Hydrotheca seated in distal half of internode in regions

where no athecate internodes occur and in centre of internode in regions with

athecate internodes.

Hydrotheca cup-shaped, completely adnate, widening to margin, with no

intrathecal septum, with more or less straight abcauline wall and convex

adcauline wall, 0,08-0,10 mm in abcauline depth and 0,11-0,12 mm in marginal

diameter. Margin oblique.

Nematothecae all two-chambered and movable, with funnel-shaped distal

chamber.

Gonothecae borne on hydrocladial apophyses of stem. Only the male

known: without nematothecae, smooth, elongated, with terminal aperture,

held at a small angle (10-15°) to stem.

Distribution. Endemic to South Africa.

390 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. Type locality and only record: off Natal in 440 m,

29/31 (d)

Plumularia filicaulis Kirchenpauer, 1876

Fig. 123H-L

Plumularia filicaulis Kirchenpauer, 1876: 47, pl. 5 (fig. 6). Bale, 1884: 134, pl. 11 (figs 6-7),

pl. 19 (figs 41-42). Leloup, 1934: 4. Millard, 1958: 209, fig. 13D-E.

Diagnosis. Hydrorhiza creeping on weed, flattened and ribbon-shaped, with

very thick perisarc and internal projections, giving rise to both pinnate and

simple stems.

Pinnate stem unfascicled, reaching a height of 6 mm, bearing alternate

hydrocladia, divided into regular internodes by distinct nodes. Lowest nodes

very strong and very oblique, resembling hinge-joints, becoming less marked

and less oblique distally. Each internode bearing one hydrocladial apophysis

in centre or in distal half and two median nematothecae, one near the base and

one next to the apophysis. Mamelon present on upper surface of apophysis.

The two rows of hydrocladia not in the same plane, but displaced towards the

anterior surface.

Hydrocladium bearing up to six hydrothecae on anterior surface, with

perisarc of anterior surface greatly thickened around origins of hydrothecae

and nematothecae; consisting of one short, athecate, anematothecate internode;

sometimes a second short athecate internode with one nematotheca; then

alternate long thecate and short athecate internodes terminated by transverse

and oblique nodes respectively. Athecate internodes other than the first with

one median nematotheca. Thecate internodes with three nematothecae, one

median inferior reaching to base of hydrotheca and one pair laterals not reaching

to thecal margin.

Simple stem arising from apophysis of hydrorhiza, reaching 5 mm in height,

representing an independent hydrocladium and exactly similar to a hydro-

cladium in structure except that the first two nodes (bounding the first athecate

internode) are very strongly developed and resemble hinge-joints.

Hydrotheca cup-shaped, adnate for only a small part of adcauline wall,

with an adcauline intrathecal septum and a curved abcauline wall, 0,09-0,15 mm

in height and 0,18-0,3 mm in marginal diameter. Margin forming an angle of

about 45° with hydrocladium, produced to form a peak on the adcauline and on

the abcauline side.

Median nematotheca immovable, two-chambered, with very small basal

chamber and large curved distal chamber in which the adcauline wall is almost

completely cut away. Lateral nematotheca movable, two-chambered, with very

small basal chamber and long, funnel-shaped distal chamber.

Gonothecae borne on hydrorhiza and firmly applied to substratum,

flattened, with very thick perisarc, irregularly ovate in outline, with a circular

aperture on upper surface near one end and a variable number of minute pores

on upper surface.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 39]

AWB GA

Fig. 123.

Plumularia antonbruuni. A and.B, hydrocladia, A with only thecate internodes, B with alternate

athecate and thecate internodes; C, part of stem with gonothecae and origins of hydro-

cladia; D, stem.

Plumularia mossambicae sp. nov., from holotype. E, stem; F, part of stem showing origins of

hydrocladia; G, hydrocladium.

Plumularia filicaulis. H, hydrocladium; J, stem in anterior view showing origins of hydrocladia;

K, male gonophore; L, fertile colony growing on weed, with pinnate stems, simple stems

and gonothecae.

Scale: D, E and L in cm, the rest in mm/10.

392 ANNALS OF THE SOUTH AFRICAN MUSEUM

Variation and remarks. This species shows considerable variation in its method of

branching. Apart from its ability to exist in a pinnate and a simple form in the

same colony, the simple stem occasionally produces a few irregular branches,

and in one case a branch was seen to arise from within a hydrotheca. Further,

in some cases the terminal part of a pinnate stem, after the origin of the last

hydrocladium, may bear hydrothecae and is thus continued as a hydrocladium.

Thus, in its ability to bear cauline hydrothecae and also in the closely

packed hydrothecae and the immovable median nematothecae, the species

shows relationships with the subfamily Halopterinae.

Distribution outside South Africa. Chile (type locality), south-east Madagascar,

Australia. (var. japonica from Japan.)

Distribution in South Africa. From South West Africa to Hermanus; Mocam-

bique; littoral to 27 m. 26/15 (1), 33/18, 34/18 (s), 34/19, 26/32 (s), 24/35 (s),

23/35 (1)

Plumularia lagenifera Allman, 1886

Fig. 124A—D

?Aglaophenia Gaimardi Lamouroux, 1824: 611, pl. 95 (figs 9-10).

spas ie lagenifera Allman, 1886: 157, pl. 26 (figs 1-3). Broch, 1914: 26. Millard, 1957:

is ees lagenifera var. septifera Torrey, 1902: 78, pl. 11 (figs 101-102). Ritchie, 1909: 87,

2Plumularia setacea var Gaimardi: Billard, 1909: 325, fig. 10.

Diagnosis. Hydrorhiza creeping, with or without internal perisarcal thickenings,

flattened, bearing nematothecae. Stem unfascicled, reaching 45 mm in height,

bearing alternate hydrocladia, divided into regular internodes by straight or

slightly oblique nodes. Each internode bearing one hydrocladial apophysis in

distal half and two nematothecae, one near base and one in axil of apophysis.

Three or four internodal septa, including one near base, one near distal end

and one in apophysis. Mamelon present on upper surface of apophysis. The

two rows of hydrocladia not in one plane but displaced towards the anterior

surface.

Hydrocladium bearing hydrothecae on upper surface, consisting of alternate

short athecate and long thecate internodes terminated by oblique and transverse

nodes respectively. First athecate internode without nematothecae, with one

internodal septum. Other athecate internodes with one median nematotheca

and one or two internodal septa. Thecate internodes with three nematothecae,

one median inferior seated well below hydrotheca or just reaching its base and

one pair laterals overreaching thecal margin, and with at least two internodal

septa including one near base and one near distal end.

Hydrotheca cup-shaped, completely adnate, narrowing to margin, with no

intrathecal septa, with abcauline wall distinctly convex and thickened, at

least at margin, 0,06-0,17 mm in abcauline depth and 0,07-0,14 mm in marginal

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 393

diameter. Margin perpendicular to hydrocladium or almost so. Hydranth with

about 17 tentacles.

Nematothecae all two-chambered and movable, with adcauline wall slightly

lower than abcauline.

Gonothecae borne on hydrocladial apophyses of stem, dimorphic, male

and female on separate colonies, without fematothecae, compressed, ovate in

outline, with terminal aperture. Female about twice as long as broad, with

aperture mounted on slender curved neck. Male about three times as long as

broad, with shorter and less obviously curved neck.

Variation. A form described by Torrey as var. septifera occurs, in which the

perisarc is in general much thicker and all internodes and hydrothecae are

shorter. Thus the internodal septa are stronger, the whole abcauline wall of the

hydrotheca is thickened, and the hydrotheca is wider than deep in contrast to

the normal form which is deeper than wide. Internal thickenings of perisarc

also occur in the hydrorhiza. This appears to be a growth-form only and all

intermediate stages occur between it and the normal form.

Minor variations occasionally encountered include stolonization from the

distal end of the stem, extra cauline internodes without hydrocladia, extra

athecate internodes in the hydrocladia, extra cauline nematothecae (though not

in axils) and branching hydrocladia. The curvature in the neck of the gonotheca

varies considerably from almost straight to so strongly curved that the aperture

faces downwards.

Remarks. This species is closely related to P. setacea, differing only in the shape

of the hydrotheca. Discovery of intermediate forms may necessitate the

combination of the two.

Distribution outside South Africa. West coast of America from Chile to Alaska.

Type locality: Vancouver Island.

Distribution in South Africa. South West Africa to Hermanus; Knysna Estuary;

littoral to 51 m. 26/15 (1, s), 28/16 (s), 32/17 (1), 32/18 (s), 33/17 (s), 33/18 (, s),

34/18 (s), 34/19, 34/23 (s)

Plumularia mossambicae sp. nov.

Fig. 123E-G

Material. The holotype, SAM—H1866, includes a single stem 12 mm in height.

Position: off Mocambique, 24°46’S/35°18’E, 110 m, 18/8/1964.

Description. Hydrorhiza branching and filamentous for penetration of sub-

‘stratum. Stem unfascicled, bearing alternate hydrocladia, the two rows in one

plane. Nodes transverse, not very distinct, irregular. Each internode bearing

1-5 hydrocladia (of which the first two are opposite, though broken off short,

and the rest alternate). No internodal septa in main axis. Hydrocladial apophysis

with a mamelon on upper surface and a weak internodal septum. Cauline

ANNALS OF THE SOUTH AFRICAN MUSEUM

WW LALULESS SI

‘ SSSA

RSS WS WY) ds

F\ SSAA

4 yyy yyy

Ree DD ay \

— Px Wy »» UY,

6 &

Fig. 124.

Plumularia lagenifera. A and B, hydrocladia, both from same sample; C, colony; D, stem in

anterior view showing female gonothecae and origins of hydrocladia.

Plumularia setacea. E, colony; F, part of stem showing male gonotheca and origins of hydro-

cladia; G, hydrocladium; H, female gonotheca; J and K, stem and hydrocladium of

epizootic form.

Scale: C and E in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 395

nematothecae: two in axil of each apophysis, none on main axis of stem.

Hydrocladium very slender, with one athecate internode of moderate

length, generally followed by long thecate internodes only, but sometimes with

intermediate athecate internodes present towards the distal end. First athecate

internode without nematothecae, with two internodal septa, one proximal and

one distal. Thecate internode with two poorly defined internodal septa, one

proximal and one distal; with one median inferior nematotheca well below

the hydrotheca, one pair of laterals overtopping thecal margin and with or

without one median superior nematotheca. Intermediate internode, when pre-

sent, with two poorly defined internodal septa, one proximal and one distal,

and one median nematotheca. When no athecate internodes occur the hydro-

theca is seated in the proximal half of the internode. When intermediate inter-

nodes occur, they appear to be formed by cutting off the distal end of a thecate

internode together with the median superior nematotheca. The previous thecate

internode is then shorter than normal with the hydrotheca seated more or less in

the centre and there is no median superior nematotheca. In one case the proximal

end of the first thecate internode is cut off, taking with it the median inferior

nematotheca.

Hydrotheca completely adnate, with more or less straight abcauline wall

and slightly convex adcauline wall. Width at margin exceeding depth.

Nematothecae all two-chambered and movable, very large, especially the

laterals which may be nearly twice the length of the hydrotheca.

Gonothecae absent.

Measurements (mm)

Stem internode, length .. dex fe oF a: a 2.150559 -2,10

diameter at node... ae me ae - oe ‘ie 0,08

Hydrocladium, first athecate internode, length + ys .. 0,22-0,24

normal thecate internode, length .. i o hs .. 0,72-0,84

diameter in centre WF ne a = ee a 0,04

athecate internode, other than first, length ES: «s .. Q,31-0,44

Hydrotheca, depth abcauline .. e. ae sf cy. .. 0,06—0,075

diameter at margin .. i: se a 5 ue .. 0,08-0,085

Lateral nematotheca, length .. 2.8 Bs ms af .. 0,09-0,11

Remarks. This species is closely related to Plumularia antonbruuni. It differs

from it in the following characters:

(i) The stem internodes bear more than one hydrocladium each.

(ii) There are no cauline nematothecae on the main axis.

(iii) The first internode of the hydrocladium is not particularly short.

(iv) The hydrotheca is seated on the proximal half of the internode, and inter-

mediate athecate internodes, when present, are cut off from the distal parts

of the thecate internodes.

The species is also close to P. ventriculiformis Marktanner-Turneretscher,

1890, resembling it in the arrangement of the stem internodes (though Mark-

tanner mentions an occasional cauline nematotheca) and in the position of the

396 ANNALS OF THE SOUTH AFRICAN MUSEUM

hydrotheca on the thecate internode. It differs in the constant presence of an

athecate internode at the base of each hydrocladium.

Distribution. Endemic to South Africa.

Distribution in South Africa. The only record is the type material recorded

above. 24/35 (d).

Plumularia obliqua (Johnston, 1847)

Fig. 125A-B

Laomedea obliqua Johnston, 1847: 106, pl. 28 (fig. 1).

Plumularia obliqua: Bale, 1884: 138, pl. 12 (figs 1-3). Hincks, 1868: 304, fig. 36, pl. 67 (fig. 1).

Pennycuik, 1959: 180. Millard & Bouillon, 1974: 34, fig. 8A—D.

?Monotheca posidoniae Picard, 1951: 341, fig. 2B.

Diagnosis. Hydrorhiza creeping on weed, with internal projections of perisarc.

Stem unfascicled, reaching a maximum height of 5 mm, bearing up to 13

alternate hydrocladia, divided into internodes by straight nodes, each bearing

one hydrocladial apophysis in distal half. The two rows of hydrocladia in one

plane. Each internode bearing two nematothecae (one in axil of apophysis and

one on opposite side of internode). Mamelon present on upper side of apophysis.

At least three internodal septa, one proximal, one distal and one in apophysis.

Hydrocladium bearing one hydrotheca only, consisting of two internodes,

one short and athecate, and one long and thecate. Athecate internode with one

or two internodal septa and no nematothecae. Thecate internode bearing the

hydrotheca on the anterodistal surface, narrowed and curved round the thecal

wall, then widening to a broad, rounded distal end terminating very slightly

below thecal margin. Three nematothecae: one median inferior reaching

approximately to thecal base and one pair laterals above thecal margin.

Hydrotheca slightly compressed, cup-shaped, completely adnate, with a

smoothly convex to straight abcauline wall, adcauline wall with margin everted

over end of internode, with no intrathecal septum, 0,17-0,2 mm in abcauline

height and 0,12-0,17 mm in marginal diameter.

Nematothecae all two-chambered and movable. Median and cauline

nematothecae with adcauline wall lower than abcauline. Lateral nematotheca

deeply cut away on upper face.

Gonotheca (not reported from South Africa) very large, ovate, truncated

distally (Hincks).

Variation. Extra regenerative nodes often appear in the stem. The thickness of

the perisarc is variable, and young hydrocladia have no internodal septa behind

the hydrotheca while old ones have two strong septa.

Distribution outside South Africa. North Atlantic, Mediterranean, Australia,

Japan. Type locality: Brighton, England.

Distribution in South Africa. Inhaca and Transkei coast, littoral to 15 m.

31/29 (1), 26/32(1,'s)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 397

Fig. 125.

Plumularia obliqua. A, stem; B, hydrocladium.

Plumularia pulchella. C, hydrocladium; D, stem with gonothecae.

Plumularia spinulosa. E, stem with gonotheca; F-J, different views of hydrocladium, F from

the side (lateral nematotheca removed), G, oblique view showing opening of funnel into

septum, H, from behind, and J from above looking onto septum.

Scale in mm/10.

398 ANNALS OF THE SOUTH AFRICAN MUSEUM

Plumularia pennycuikae Millard & Bouillon, 1973

Fig. 126A-—C

Plumularia sp. Pennycuik, 1959: 183, pl. 3 (fig. 7).

Plumularia pennycuikae Millard & Bouillon, 1973: 85, fig. LON, P. Hirohito, 1974: 39, fig. 18.

Diagnosis. Stem unfascicled, branched or unbranched, reaching 13 mm in height,

bearing alternate hydrocladia, divided into internodes by transverse nodes.

Each internode bearing one hydrocladial apophysis at distal end and three

nematothecae, two in axil and one on opposite surface, usually with one inter-

nodal septum at proximal end. Mamelon present on upper surface of apophysis.

Branches, when present, arising next to hydrocladium from same apophysis,

similar to stem. The two rows of hydrocladia in same plane.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

very short athecate and anematothecate internode terminated by an oblique

node, then alternate long thecate and shorter athecate internodes terminated by

transverse and oblique nodes respectively. First internode with two internodal

septa, one proximal and one distal. Other athecate internodes with one median

nemathotheca, with or without septa. Thecate internodes with three nemato-

thecae, one median inferior reaching approximately to base of hydrotheca and

one pair laterals not reaching thecal margin, without septa. Hydrotheca seated

more or less in centre of internode.

Hydrotheca cup-shaped, adnate for about half adcauline length or a little

more, with no intrathecal septum, with straight abcauline wall and with

adcauline wall distinctly concave in free section, 0,13-0,15 mm in abcauline

length and 0,12-0,15 mm in marginal diameter. Margin oblique.

Nematothecae all two-chambered and movable, with funnel-shaped distal

chamber. Adcauline wall lower than abcauline in median nematothecae.

Gonothecae (not reported from South Africa) borne on apophyses of stem;

female small, oval to spherical, containing one egg which develops into a

planula in situ. Male gonotheca unknown.

Distribution outside South Africa. Seychelles, Queensland, Australia, and Japan.

Type locality: Silhouette Island, Seychelles.

Distribution in South Africa. Santa Carolina in Mocgambique only. 21/35

Plumularia pulchella Bale, 1882

Fig. 125C-D

Plumularia pulchella Bale, 1882: 30, pl. 15 (fig. 6). Bale, 1884: 140, pl. 12 (fig. 6), pl. 19 (fig.

37). Totton, 1930: 221, fig. 58. Ralph, 19615: 39, fig. Sc-e.

Plumularia flexuosa Bale, 1894: 115, pl. 5 (figs 6-10).

Plumularia (Monotheca) flexuosa: Stechow, 1925a: 499.

Diagnosis. Hydrorhiza creeping, with or without internal projections of perisarc.

Stem unfascicled, reaching a height of about 10 mm, bearing up to 29 alternate

hydrocladia. Divided into regular internodes by distinct nodes, each bearing

one hydrocladial apophysis in distal half. The two rows of hydrocladia in the

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 399

same plane or displaced very slightly towards the anterior surface. Each inter-

node bearing three nematothecae (one in basal half, two in axil of apophysis).

Mamelon present on upper surface of apophysis.

Hydrocladium bearing one hydrotheca only. Consisting of two internodes,

one short and athecate and one long and thecate. Athecate internode with two

internodal septa and no nematothecae. Thecate internode bearing the hydrotheca

on the upper surface, with its distal end narrowed and curved round the adcauline

thecal wall, then widening to a broadly rounded distal end terminating just

below the thecal margin. Three nematothecae: one median inferior reaching

above base of hydrotheca to about a third of its height, and one pair laterals

overtopping thecal margin.

Hydrotheca cup-shaped, completely adnate, widening distally and curved

away from hydrocladium, with concave abcauline wall, with no intrathecal

septa, 0,09-0,13 mm in depth and 0,10-0,14 mm in marginal diameter. Margin

almost perpendicular to hydrocladium.

Nematothecae all two-chambered, movable and funnel-shaped.

Gonothecae borne on hydrocladial apophyses, usually smooth, ovate,

tapering below to slender, curved base, truncated distally, with wide terminal

aperture.

Variation. The stem occasionally gives off 1-3 branches. These replace hydro-

cladia and are quite irregular in arrangement. At the base of the stem there may

be up to four irregular internodes, occasionally with nematothecae.

The presence or absence of internodal septa is variable. Usually there is

one in each hydrocladial apophysis, two in the athecate internode of the

hydrocladium and up to two in the thecate internode behind the hydrotheca.

Regeneration after injury may result in extra irregular internodes in the

stem or in the hydrocladia. Thus the latter may have two athecate internodes

at the base, of which one may bear a nematotheca.

The gonothecae are variable in appearance, being sometimes smooth and

sometimes irregularly corrugated. The aperture is usually at right angles to

the axis, but it may be slightly oblique. Some of the gonothecae have a raised

collar around the opening.

Distribution outside South Africa. Australia (type locality), New Zealand, Vema

Seamount (South Atlantic), Japan.

Distribution in South Africa. West coast of Cape Peninsula to Natal, littoral to

100 m. 33/18 (1), 34/18 Cl, s), 35/19 (s), 35/20 (d), 34/22 (s), 34/23 (s, h), 33/25

(s), 34/25 (s), 33/27 (s), 32/28 (s), 29/31 (s), 28/32 (d)

Plumularia setacea (Linnaeus, 1758)

Fig. 124E-K

Sertularia setacea Linnaeus, 1758: 813.

Plumularia setacea: Hincks, 1868: 296, fig. 34, pl. 66 (fig. 1). Broch, 1914: 25, pl. 1 (fig. 1).

Ralph, 19615: 33, figs 3e, 4a, c-d. Vervoort, 1966b: 142, fig. 43. Millard, 1968: 278,

fig. SF-H. Millard, 1973: 27, fig. 3.

400 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis. Hydrorhiza creeping. Stem unfascicled, generally 10-20 mm in

height (maximum 40 mm), bearing alternate hydrocladia, divided into regular

internodes by transverse or slightly oblique nodes. Each internode bearing one

hydrocladial apophysis in distal half and two nematothecae, one near base on

side opposite to apophysis and one on apophysis. Internodal septa present or

absent; when present including one in proximal region, one in distal region and

one in apophysis. Mamelon present on upper surface of apophysis. The two

rows of hydrocladia not in one plane but displaced towards the anterior surface.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

very short athecate internode, then alternate long thecate and shorter athecate

internodes terminated by transverse or slightly oblique nodes. First internode

without nematothecae, with one internodal septum. Other athecate internodes

with one median nematotheca and two internodal septa, one proximal and one

distal. Thecate internodes with three nematothecae, one median inferior not

reaching base of hydrotheca and one pair laterals overreaching thecal margin,

and with at least two internodal septa including one near base and one near

distal end. Hydrotheca generally seated in centre of internode.

Hydrotheca cup-shaped, completely adnate, widening to margin, with no

intrathecal septum, with straight abcauline wall, 0,06—-0,12 mm in abcauline

depth and 0,08—0,12 mm in marginal diameter. Margin slightly oblique.

Nematothecae all two-chambered and movable, with funnel-shaped distal

chamber.

Gonothecae borne on hydrocladial apophyses of stem, dimorphic, male

and female on separate colonies, without nematothecae, elongated, with terminal

aperture. Male very slender, with small aperture. Female larger, compressed,

with larger aperture on tubular neck, which may be curved slightly to one side,

containing about eight eggs which develop into planulae in situ.

Variation. The hydrotheca of this species is known to vary in size. Normally it

is 3-3 length of the internode, but Broch (1914) distinguished a forma micro-

theca in which it is only }-+ length of the internode. In South Africa there are all

variations between these limits.

An epizootic form of the species commonly occurs on other hydroids (e.g.

on Nemertesia cymodocea and Salacia articulata), which is characterized by a

greater or lesser degree of stunting. The stem is usually under 10 mm in height,

and the hydrocladia are short, bearing one, or at most, four hydrothecae. The

nematothecae are also reduced in size, especially the laterals which may be

minute

Less important variations include branching of the stem, variation in length

of stem internodes, the placing of the two rows of hydrocladia in one plane,

extra internodal septa and extra nematothecae (e.g. on the stem internodes and

on the thecate hydrocladial internodes).

Because of the possibility of confusion between this species and P. warreni

and P. strictocarpa, only records with mature gonophores have been quoted

below.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 401

Distribution. Cosmopolitan. Type locality: U.K.

Distribution in South Africa. All round the coast, common in the littoral region

and shallow water, rare in deeper water to 430 m. 26/15 (1), 32/18 (1, s), 33/17 (s),

33/18 (1, s), 34/18 (1, s, h), 35/19 (s), 34/20 (1), 34/22 (s), 34/23 (s), 33/25 (s, h),

34/25 (s) 33/27 (1), 31/29 (1), 31/30 (1), 30/30 (1), 29/31 (1, s, d), 28/32 (s), 25/32 (s)

Plumularia spinulosa Bale, 1882

Fig. 125E-J

Plumularia spinulosa Bale, 1882: 30, pl. 15 (fig. 8). Bale, 1884: 139, pl. 12 (figs 11-12). Bale,

1888: 783, pl. 19 (figs 11-13). Warren, 1908: 320. Millard, 1962: 301.

Monotheca spinulosa var. obtusa Stechow, 1923c: 224.

Plumularia spinulosa var. obtusa: Millard, 1957: 232.

Plumularia spinulosa var. typica: Millard, 1958: 212.

Plumularia spinulosa var. spinulosa: Ralph, 19616: 37, fig. 4i-j.

Diagnosis. Hydrorhiza creeping, strengthened by internal projections of perisarc.

Stem unfascicled, reaching a height of about 5 mm, bearing up to 18

alternate hydrocladia; divided into regular internodes by distinct nodes, each

bearing one hydrocladial apophysis. The two rows of hydrocladia in the same

plane or displaced slightly towards the anterior surface. Each internode usually

with three internodal septa (one near base, one near distal end and one in

apophysis) and bearing two nematothecae (one near base and one in axil of

apophysis). Mamelon present on upper surface of apophysis.

Hydrocladium bearing one hydrotheca only. Consisting of two internodes,

one short and athecate and one long and thecate. Athecate internode with one

internodal septum and no nematothecae. Thecate internode bearing the hydro-

theca on the upper surface and with its distal end curved round the adcauline

thecal wall, ending in a short, bluntly pointed spine at or above the thecal

margin. Usually one or two internodal septa behind adcauline thecal wall.

Three nematothecae: one median inferior reaching approximately to base of

hydrotheca and one pair of laterals overtopping thecal margin.

Hydrotheca laterally compressed, completely adnate, with convex abcauline

wall; with a strong adcauline intrathecal septum projecting about half-way

across cavity and with a funnel-shaped opening into it on each side; with an

abcauline intrathecal septum near base, so that expanded hydranth is twisted

into an S-shape. Margin perpendicular to hydrocladium, somewhat sinuated

in adcauline region. Hydrotheca 0,12-0,18 mm in depth and 0,10-0,17 mm in

marginal diameter. Hydranth with about 13 tentacles.

Nematothecae all two-chambered and movable. Wall of distal chamber

lower on adcauline side.

Gonothecae borne on hydrocladial apophyses, smooth, deep-campanulate

and sometimes curved asymmetrically, with a wide terminal aperture, containing

one or two gonophores.

Variation. The most obvious variations are in the length of the terminal hydro-

cladial spine, which may just reach the thecal margin or may be produced above

402 ANNALS OF THE SOUTH AFRICAN MUSEUM

it, and in the position of the hydrocladial apophysis, which may arise either

from the distal end of the stem internode or from its centre. Both variations may

occur within the same colony.

Minor variations include the presence or absence of one or two irregular

internodes without hydrocladia or nematothecae at the base of the stem, the

position of the basal nematotheca on the stem internode, and the number of

internodal septa which may be greater or less than the number given in the

diagnosis depending on the strength of the perisarc in the colony as a whole.

A few instances of a branching stem have been seen.

Distribution outside South Africa. Australia (type locality), New Zealand, Japan,

Vema Seamount (South Atlantic).

Distribution in South Africa. False Bay to Natal, littoral to 56 m. 34/18 (s),

34/22 (Ss), 33/25 (S),. 34/25), 33/26 (G); 33/27 C's); 32/286) 531/29.) ss SOne:

S0/S0KEs)s 29) Biles)

Plumularia strictocarpa Pictet, 1893

Fig. 126D-E

Plumularia strictocarpa Pictet, 1893: 55, pl. 3 (figs 47-49). Stechow & Uchida, 1931: 565, fig.

12, pl. 15 (ig. 6). Millard & Bouillon, 1973: 88, fig. 11A—B.

Diagnosis. Stem unfascicled, reaching 10 mm in height, bearing alternate hydro-

cladia, divided into regular internodes by transverse nodes. Each internode

bearing one hydrocladial apophysis at distal end and two nematothecae, one in

axil and one on opposite side of internode. Internodal septa usually absent.

Mamelon present on upper surface of apophysis. The two rows of hydrocladia

in one plane.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

very short athecate internode terminated by an oblique node, then alternate

long thecate and shorter athecate internodes terminated by straight or slightly

oblique nodes. First internode without nematothecae, with one internodal

septum. Other athecate internodes with one median nematotheca and usually

two internodal septa, one proximal and one distal. Thecate internodes with

three nematothecae, one median inferior seated well below base of hydrotheca

and one pair laterals overreaching thecal margin, and with at least one internodal

septum at proximal end. Hydrotheca seated more or less in centre of internode.

Hydrotheca cup-shaped, almost completely adnate, widening to margin,

with no intrathecal septum, with straight abcauline wall, 0,06-0,08 mm in

abcauline depth and 0,08-0,11 mm in marginal diameter. Margin slightly

oblique.

Nematothecae all two-chambered and movable, with funnel-shaped distal

chamber.

Gonothecae borne on lower part of stem only, on apophyses of hydrocladia

which have usually fallen off, elongate-oval, transversely annulated, with

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 403

Fig. 126.

Plumularia pennycuikae. A, stem; B, part of stem showing origins of hydrocladia;

C, hydrocladium.

Plumularia strictocarpa. D, lower part of stem with female gonothecae; E, hydrocladium.

Plumularia warreni. F, hydrocladium; G, anterior view of stem with female gonothecae and

their marsupia; H, stem with male gonothecae.

Scale: A in mm, the rest in mm/10.

404 ANNALS OF THE SOUTH AFRICAN MUSEUM

terminal aperture and no neck, reaching 1,0 mm in length and 0,6 mm in

maximum diameter. Young ones shorter and truncated.

Remarks. This species cannot be distinguished from P. setacea in the absence of

gonothecae.

Distribution outside South Africa. Circumglobal in tropical and subtropical

waters. Type locality: Bay of Amboine, East Indies.

Distribution in South Africa. Santa Carolina in Mogambique only. 21/35

Plumularia warreni Stechow, 1919

Fig. 126F—H

Plumularia tenuis Warren, 1908: 316, fig. 13.

Plumularia warreni Stechow, 19196: 119. Millard, 1958: 213. ?Pennycuik, 1959: 181, pl. 4.

Mammen 19€5b: 299, figs 94-95.

Diagnosis. Hydrorhiza creeping, usually on weeds, with internal projections of

perisarc. Stem unfascicled, reaching a maximum height of 22 mm, bearing

alternate hydrocladia, divided into regular internodes by transverse nodes.

Each internode bearing one hydrocladial apophysis in distal half and two

nematothecae, one near the base on anterior surface and one on apophysis.

Internodal septa present or absent; when present including one in proximal

region, one in distal region and one in apophysis. Mamelon present on upper

surface of apophysis. The two rows of hydrocladia usually not in one plane but

displaced towards anterior surface.

Hydrocladium bearing kydrothecae on upper surface, consisting of one

very short athecate internode, then alternate long thecate and shorter athecate

internodes terminated by transverse or oblique nodes. First internode without

nematothecae, with one internodal septum. Other athecate internodes with one

medial nematotheca and usually two internodal septa, one proximal and one

distal. Thecate internodes with three nematothecae, one median inferior not

reaching to base of hydrotheca and one pair laterals overreaching thecal margin,

and usually with at least two internodal septa including one near base and one

near distal end. Hydrotheca seated more or less in centre of internode.

Hydrotheca cup-shaped, completely adnate, widening to margin, with no

intrathecal septum, with more or less straight abcauline wall, 0,06-0,11 mm in

abcauline depth and 0,09-0,14 mm in marginal diameter. Margin slightly

oblique. Hydranth with 18-20 tentacles.

Nematothecae all two-chambered and movable, with funnel-shaped distal

chamber.

Gonothecae borne on hydrocladial apophyses of stem, dimorphic, male

and female on separate colonies, without nematothecae, transverse-oval in

section, with terminal aperture. Male elongated, often slightly curved, with

irregular outline, reaching 0,8 mm in length. Female elongate-oval, smooth or

with irregular outline, without neck, eggs extruded into an external marsupium,

where they develop into planulae; young ones with truncated distal end.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 405

Variation. Occasionally the stem branches near the base.

Remarks. This species cannot be distinguished from P. setacea in the absence of

gonothecae. A form of the species occurs on the west coast of the Cape Peninsula

in which the hydrocladia have only one or two thecate internodes and in which

there is usually a deficiency in the nematotheca complement, in many stems

only the laterals remaining. The female gonophores are also larger than those

from the east coast.

Distribution outside South Africa. Queensland, Madagascar, Seychelles, and

southern India. Type locality: Natal, South Africa.

Distribution in South Africa. Coast of Natal and Mocambique, littoral, with two

records from the west coast of the Cape Peninsula. 33/18 (1), 34/18 (1), 29/31 (1),

D732 (); 26/32 (1), 24/35 (S), 23/25 (), 21/35

Plumularia wasini Jarvis, 1922

Fig. 127

Plumularia wasini Jarvis, 1922: 349, fig. 1, pl. 26 (fig. 23). Millard, 1962: 301, fig. 8.

Diagnosis. Hydrorhiza creeping. Stem unfascicled, reaching 36 mm in height,

bearing alternate hydrocladia, divided into internodes of irregular length by

transverse nodes, of much greater diameter than hydrocladia. Each internode

bearing 1-5 short hydrocladial apophyses, the two rows of hydrocladia in the

same plane. No internodal septa. Nematothecae numerous, in two longitudinal

rows. No mamelon.

Hydrocladium bearing hydrothecae on upper surface, consisting of alter-

nate short athecate and longer thecate internodes terminated by oblique and

transverse nodes respectively. Each athecate internode with one or two median

nematothecae. Each thecate internode with one median inferior nematotheca

not quite reaching base of hydrotheca, one pair pedicellate laterals not quite

reaching margin, and one or a pair of minute median superior behind adcauline

wall of hydrotheca. No internodal septa.

Hydrotheca cup-shaped, wider than deep, adnate for about half height,

then free, with no intrathecal septa, with more or less parallel adcauline and

abcauline walls, 0,12-0,2 mm in abcauline height and 0,2 mm in marginal

diameter. Margin forming an angle of about 40° with hydrocladium.

Nematothecae two-chambered and movable, except the superiors, which

are minute, one-chambered and immovable, all with the adcauline wall cut

away to a certain extent.

Gonothecae borne on hydrocladia immediately below the hydrothecae,

dimorphic, pedicellate, bearing two or three large nematothecae, female(?)

flattened pear-shaped, large and on first thecate internode, male smaller and

round in section and on thecate internodes other than the first, both with

terminal aperture.

406 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 127.

Plumularia wasini. A, fertile stem; B, anterior view of stem showing male (small) and female

(large) gonothecae and origins of hydrocladia; C, hydrocladium.

Scale: A in cm, the rest in mm/10.

Variation. The most marked variation is in the length of the stem internodes

and in the structures which they bear. Although the hydrocladia are spaced

fairly evenly, the number borne on a stem internode varies from one to five

and the length of the internode varies accordingly, as does the number of nema-

tothecae (2-14). The latter are arranged in two fairly distinct longitudinal rows,

which may lie along the lateral surfaces or on the anterior surface. Here and

there nematothecae may be displaced from their rows.

The straight nodes on the hydrocladia are sometimes indistinct. One

instance of a branching hydrocladium has been seen.

Distribution outside South Africa. Tropical East Africa (type locality).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 407

Distribution in South Africa. Natal to Mogambique (Santa Carolina), 18-100 m.

B29 (5), 29/351 (8), 29/32 (Ss), 28/32 (d); 217/35

Subfamily Aglaopheniinae

Diagnosis. Stem erect, branched or unbranched, fascicled or unfascicled, bearing

hydrocladia. No cauline hydrothecae. Hydrocladia arising from a single axial

tube in fascicled stems, homomerous, bearing close-set hydrothecae generally

on the anterior surface. Hydrothecae generally completely adnate and with

toothed margin. Paired lateral nematothecae always present and fused to

hydrothecae; generally (always, in South African species) at least three nema-

tothecae to each hydrotheca, one pair laterals and one median inferior which

may or may not be fused to hydrotheca. All nematothecae one-chambered and

immovable, though often with more than one opening, of which one may

communicate with cavity of hydrotheca. Gonothecae unprotected, or protected

by simple nematophore-bearing phylactocarps, or aggregated into a corbula.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Gonothecae unprotected .. a ae a Gymnangium p. 432

— Gonothecae protected by ACCESSOry. Secneies Er 2

2. Gonothecae aggregated in a corbula, which Se aera a ia gears a ee

secondary ribs a 3

— No true corbula Bas gonothecae solitary and protected by unbranched phylacto-

Canps) =. as = ao 0 : 28,24

3. Each corbula rib re a Perothccs at its ee ee ey S ire p. 453

— Corbula ribs without hydrothecae at their bases .. ie Se Aglaophenia p. 407

4. Phylactocarp formed from a modified hydrocladium .. Lytocarpus p. 446

— Phylactocarp an appendage of a hydrocladium, which is itself unmodified “s : 5

5. Hydrocladia arranged in a spiral around stem .. ee: ae Se baneabea

- Hydrocladia pinnately arranged in two longitudinal rows ae Cladocarpus p. 416

Genus Aglaophenia Lamouroux, 1812

Diagnosis. Stem branched or unbranched, bearing alternate hydrocladia.

Hydrocladia unbranched. Hydrotheca sac-shaped to deep, usually with toothed

margin and an adcauline intrathecal septum. Median inferior nematotheca at

least partly adnate to hydrotheca, of variable length. Gonothecae in corbula

formed by modified hydrocladium bearing secondary ribs. Ribs bearing nemato-

thecae but no hydrothecae.

Type species: Sertularia pluma Linnaeus, 1758.

KEY TO SPECIES

(Doubtful species not included; for these see p. 415)

1. Stem strongly fascicled. Median inferior nematotheca adnate to hydrotheca for

entire length .. A. cupressina

— Stem unfascicled. Median inferior nematotheca not nduate fo hydrotheca for entire

length .. 2

408 ANNALS OF THE SOUTH AFRICAN MUSEUM

2. Hydrotheca with a solid perisarcal keel on abcauline surface projecting as an ‘outer

point’ beyond the abcauline marginal tooth fe .. A, latecarinata

— Hydrotheca with no perisarcal keel, median abcauline tooth simple ae .. A. pluma

Aglaophenia cupressina Lamouroux, 1816

Fig. 128A—C

Aglaophenia Cupressina Lamouroux, 1816: 169. Billard, 1913: 107, fig. 96, pl. 6. Bale, 1915:

319, pl. 47 (figs 6-8). Millard & Bouillon, 1974: 36, fig. 8E-F.

Aglaophenia macgillivrayi: Allman, 1883: 34, pl. 10, pl. 20 (figs 4-6).

Diagnosis. Stem robust, thickly fascicled, branching and rebranching irregularly

up to the fourth order, reaching a maximum height of 230 mm, bearing alternate

hydrocladia from an axial tube (though hydrocladia absent in basal parts).

Final branches (pinnae) arising from axial tube of stem at regular intervals in

subopposite pairs, unfascicled or with one or two supplementary tubes derived

from the accessory tubes of stem, bearing alternate hydrocladia. No hinge-

joints. Axial tube of pinna segmented, each internode bearing one hydrocladial

apophysis, with two nematothecae and a mamelon on the apophysis.

Hydrocladia closely set, short (1-2 mm), bearing hydrothecae on anterior

surface, divided into squarish thecate internodes by transverse nodes, proximal

internodes larger than distal ones. Each internode with two powerful internodal

septa converging towards one another anteriorly. Anterior wall of internode

with thick perisarc.

Hydrotheca deep, obconical, completely adnate, 0,3 mm in height and

0,14-0,15 mm in marginal diameter, with an adcauline intrathecal septum

arising above hydropore and running obliquely upwards across about two-

thirds of cavity. A faint longitudinal line (visible only in macerated specimens)

down centre of lateral surface. Margin smooth or sinuated, often with two or

three pairs low rounded lobes.

Median inferior nematotheca completely adnate to hydrotheca, with a

thick sigmoid intranematothecal septum arising from abcauline wall and pass-

ing obliquely downwards, with one large distal aperture sometimes bordered

by two rounded lateral lobes; with no communication with hydrotheca. Lateral

nematothecae tubular, curved, overreaching thecal margin, with one distal

aperture.

Corbulae borne on pinnae, replacing hydrocladia, with pedicel of on

thecate segment and about six pairs of alternate ribs. Each rib bearing nemato-

thecae along outer edge, the first two or three on a raised lobe, and with inner

edge fused to rib behind (corbula closed). The first rib sometimes with a free

branch on one side. Corbula reaching 2,8 mm in length and 1,1 mm in diameter.

Colour olive green to greenish black. ‘Dreaded for its stinging powers’

(Vervoort 1941).

Distribution outside South Africa. Tropical Indo-Pacific, from Zanzibar in East

Africa to the Great Barrier Reef, extending northwards in the Pacific to the Sea

of Okhotsk. Type locality: East Indies.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 409

Distribution in South Africa. Santa Carolina in Mogambique, only. 21/35

Aglaophenia latecarinata Allman, 1877

Fig. 128D-F

Aglaophenia late-carinata Allman, 1877: 56. Allman, 1886: 151, pl. 23 (figs 5-6). Millard,

1958: 213, fig. 14. .

Aglaophenia latecarinata var. madagascariensis Billard, 1907a: 387, pl. 26 (figs 18-19).

Aglaophenia latecarinata: Vervoort, 1968: 72, fig. 33.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 28 mm,

with two hinge-joints separating a short basal part from a distal part bearing

alternate hydrocladia. Basal part bearing a row of large median nematothecae

only. Distal part generally unsegmented except in terminal region where oblique

nodes separate short internodes bearing one hydrocladium each. Two or three

nematothecae to each hydrocladial apophysis, one axillary anterior, one

inferior anterior, and sometimes one axillary posterior. Mamelon present on

anterior surface of apophysis. The two rows of hydrocladia not in one plane but

shifted onto the anterior surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by transverse nodes. Internodes with two distinct

septa.

Hydrotheca sac-shaped, with a distinct adcauline intrathecal septum at

about one-third of height, 0,2—0,4 mm in height and 0,12-0,16 mm in marginal

diameter. Margin forming an angle of about 50° with internode, with nine

marginal teeth, one median abcauline and four pairs laterals. Median abcauline

tooth double, with an inner point, and a solid outer point continuous with a

keel of perisarc down abcauline wall of hydrotheca.

Median inferior nematotheca adnate to abcauline thecal wall up to level of

intrathecal septum, then free; not reaching thecal margin; with three apertures,

one terminal, one on upper surface at base of free part (these two sometimes

confluent), and one into hydrotheca; generally with a perisarcal thickening on

abcauline surface. Lateral nematotheca sac-shaped, curved, not reaching thecal

margin, with one distal aperture extending onto medial surface. Cauline

nematotheca sac-shaped, with one wide, or two small, terminal aperture(s).

Corbula replacing hydrocladium; up to 3 mm in length; with a pedicel of

one hydrotheca-bearing segment; bearing up to 10 pairs of alternate ribs. Each

rib bearing a series of nematothecae along outer edge, the first on a spinous pro-

cess, with inner edge fused to rib behind but leaving a series of openings into the

interior.

Variation. The marginal teeth of the hydrotheca are variable. The four lateral

teeth tend to be in two groups, with a more pronounced bay separating the

first and second from the third and fourth. Generally this central bay is shallow

and the two middle teeth are broad and rounded and the two outer ones narrow

and pointed. A form also occurs with a very deep central bay, taller middle

teeth and a reduced fourth (the most abcauline) tooth, which looks more like a

410 ANNALS OF THE SOUTH AFRICAN MUSEUM

Ca re we ee

ME om

ria

PAs

te /p

BAN ANS es

yi SSE

UE IO UM

i Li

SOB Gi,

QRS ey

’

Chora Temingyin

Jo alt (iri Ke ,

) Rar me peyy "

CBT ss se (2

Fig. 128.

Aglaophenia cupressina. A, stem; B, hydrocladium; C, corbula.

Aglaophenia latecarinata. D, stems; E, hydrocladium; F, female corbula (apertures between

ribs shaded).

Scale: A and D in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 411

subsidiary point on the third (var. madagascariensis Billard). This form lacks

the posterior axillary cauline nematotheca. The outer point of the median

abcauline tooth is normally longer than the inner, but in the first hydrocladial

internode it tends to be shorter than the inner and the median inferior

nematotheca reduced, not reaching to the level of the intrathecal septum.

The thickening on the abcauline wall of the median inferior nematotheca

is also variable, sometimes resembling a transverse septum and sometimes not

developed at all.

Distribution outside South Africa. Atlantic Ocean from American to African

coast and from the Azores in the north to Brazil and Angola in the south,

very common in the tropical west Atlantic on Sargasso weed; Indian Ocean

from Cargados and Madagascar. Type locality: Gulf of Mexico on floating

weed.

Distribution in South. Africa. Eastern Cape, Natal and Mocgambique, in 6-55 m.

31/29 (s), 30/30 (s), 29/31 (s), 28/32 (s), 24/34 (s)

Aglaophenia pluma (Linnaeus, 1758)

Sertularia pluma Linnaeus, 1758: 811.

Aglaophenia pluma: Millard, 1957: 235, fig. 15.

Diagnosis. Stem unfascicled, branched or unbranched, with two (or occasionally

three) hinge-joints separating a short basal part from a distal part bearing

alternate hydrocladia. Basal part without hydrocladia or nematothecae, divided

into irregular internodes by transverse nodes. Distal part divided into inter-

nodes by slightly oblique nodes, each internode bearing one hydrocladial

apophysis and three nematothecae, one axillary anterior, one axillary posterior

and one anterior inferior which may be seated on the base of the apophysis.

Mamelon present on anterior surface of apophysis. The two rows of hydrocladia

not in one plane but shifted on to anterior surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by transverse or slightly oblique nodes. Internodes

with two internodal septa.

Hydrotheca sac-shaped, expanding to margin, with an adcauline intrathecal

septum at about one-third of the height, 0,17—0,4 mm in height and 0,12—0,3 mm

in marginal diameter. Margin forming an angle of 60-70° with internode, with

nine teeth, one median abcauline and four pairs laterals of which the second

from the abcauline side may be double.

Median inferior nematotheca adnate to abcauline tnecal wall for over

two thirds of latter, then free; reaching to thecal margin or just below; with

three apertures, one terminal, one on upper surface at base of free part (these

two often confluent) and one into hydrotheca. Lateral nematotheca sac-shaped,

reaching to thecal margin or just below, with one distal aperture extending onto

median surface. Cauline nematotheca gutter-shaped.

Corbula replacing hydrocladium, consisting of a pedicel of one hydrotheca-

412 ANNALS OF THE SOUTH AFRICAN MUSEUM

bearing segment, and then 4~9 alternate paired ribs, male and female on separate

colonies. Female corbula closed; ribs, except for the first, bearing nematothecae

along outer edge and fused to rib behind by inner edge; first rib free, giving

off a branch on one side lying parallel to axis of corbula; both first rib and its

branch bearing nematothecae on both edges. Male corbula partly or completely

open; ribs, except for the first, fused in basal part and bearing nematothecae

along outer edge, free in distal part and bearing nematothecae along both edges;

first rib free and bearing nematothecae along both edges, normally unbranched.

Corbula 2-3 mm in length.

Variation. One large median nematotheca occurs on the stem internode between

the hinge-joints. The first internode beyond the hinge-joints may be longer than

usual and give rise to two hydrocladia.

On the hydrocladial internodes the length of the median inferior

nematotheca varies, though it tends to be longer in subspecies parvula.

In the corbula the branch of the first rib is occasionally absent in the female,

and occasionally present, though small and stunted, in the male.

KEY TO SUBSPECIES

1. Stem long (usually over 100 mm) and straggling, with repeated dichotomous

division .. A. p. dichotoma

Stem short (usually nade 100 sae) nad unbranched or sone branched .. 7 gee

2. Hydrotheca with all marginal teeth simple and undivided : A, p. pluma

— Hydrotheca with second paired tooth from abcauline side normally double A. p. parvula

Aglaophenia pluma pluma (Linnaeus, 1758)

Fig. 129D

Aglaophenia pluma: Hincks, 1868: 286, pl. 63 (fig. 1). Vervoort, 19465: 335, fig. 8. Rees &

Thursfield, 1965: 190.

Aglaophenia chalarocarpa Allman, 1886: 150, pl. 21 (figs 1-4). Warren, 1908: 330.

Aglaophenia pluma forma typica Bedot, 1919: 276.

Aglaophenia pluma var. typica: Millard, 1957: 238, fig. 15A.

Diagnosis. Stem short, reaching 97 mm, but usually much less, normally

unbranched.

Marginal teeth of hydrotheca of approximately equal length and not

divided. Median inferior nematotheca not reaching thecal margin.

Colour: Stem dark brown, hydrocladia light brown.

Variation. The stems may occasionally branch once or twice dichotomously,

thus tending towards subsp. dichotoma. Branches may also occur which replace

hydrocladia; these resemble stems in their structure, with a basal part without

hydrocladia separated from a distal hydrocladia-bearing part by two hinge-joints.

Rarely in the hydrotheca the second paired tooth from the abcauline side

may have a small subsidiary point, thus tending towards subsp. parvula.

Distribution. Cosmopolitan. Type locality: U.K.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 413

Distribution in South Africa. South West Africa to Natal, not common, littoral

to 49 m. 22/14 (1), 26/15 (s), 34/18 (s), 234/22, 34/23, 30/30 (1), 39/31 (I, s),

27/32 (1)

Aglaophenia pluma dichotoma (M. Sars, 1857)

Fig. 129A, C, E

Plumularia pluma var. dichotoma M. Sars, 1857: 164.

Aglaophenia dichotoma: Ritchie, 19076: 539, pl. 3 (fig. 2). Stechow, 1925a: 516.

Aglaophenia heterodonta: Ritchie, 1909 (pp): 96.

Aglaophenia pluma var. dichotoma: Millard, 1957: 239, fig. 1SB-C. Rees & Thursfield, 1965:

191.

Diagnosis. Stem long and straggling, reaching 300 mm, branching profusely in

a dichotomous manner. The two limbs of a dichotomy of equal diameter and

arising from two apophyses on a single broad stem internode, all internodes

bearing hydrocladia.

Marginal teeth of hydrotheca sharply pointed and triangular, normally

undivided. Median inferior nematotheca not, or only just reaching thecal margin.

Colour: Stem medium brown, hydrocladia cream.

Variation. In the hydrotheca the second paired tooth from the abcauline side

may have a small subsidiary point as in subsp. parvula.

Distribution outside South Africa. Atlantic, from Europe to West Africa. Type

locality: Mediterranean.

Distribution in South Africa. Northern South West Africa and Lambert’s Bay

on west coast to East London on south coast, littoral to 119 m, but most

common between 10 and 70 m, especially abundant in dredgings from False

Bay and the Agulhas Bank. 20/13 (1), 32/18 (s), 33/18 (s), 34/18 (s, 1), 34/20 (s),

34/21 (s), 34/22 (s), 35/22 (d), 34/23 (1, s, d), 33/25 (s), 34/25 (s, d), 33/26 (s),

33/27 (Ss)

Aglaophenia pluma parvula Bale, 1882

Fig. 129B, F

?Aglaophenia conferta Kirchenpauer, 1872: 32, pl. 1 (fig. 4), pl. 2 (fig. 4), pl. 3 (fig. 4).

Aglaophenia parvula Bale, 1882: 23, pl. 14 (fig. 3). Bale, 1884: 165, pl. 14 (fig. 3), pl. 17 (fig.

10). Stechow, 1925a: 516.

Aglaophenia heterodonta Jaderholm, 1903: 296, pl. 13 (figs 10-12), pl. 14 (fig. 1). Ritchie, 1909

(pp): 96.

Aglaophenia pluma var. parvula: Millard, 1957: 239, fig. 15D-F. Millard, 1958: 215. Vervoort,

1959: 307, figs 52a, 53b. Leloup, 1971: 4, fig. 2A.

Diagnosis. Stems short, growing in thick clumps on rocks, reaching 116 mm but

usually much less, unbranched or sparsely branched.

Hydrotheca with second paired tooth from abcauline side normally double,

the two points either equal in size, or with the more adcauline one larger than

the other. Median inferior nematotheca usually reaching to thecal margin or at

least to bays between the teeth.

Colour: stem dark brown, hydrocladia light brown.

414 ANNALS OF THE SOUTH AFRICAN MUSEUM

IN;

000,

SSD... OTS

ile

EAS

O77:

4%,

Fig. 129.

Aglaophenia pluma. A, fertile stem of subsp. dichotoma; B, fertile colony of subsp. parvula;

C, female corbula, subsp. dichotoma; D, E and F, hydrothecae from subsp. pluma,

dichotoma and parvula respectively.

Scale: A and B in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 415

Variation. The stem occasionally gives off one or two short branches, either

dichotomously as in subsp. dichotoma, or replacing hydrocladia.

Rarely the subsidiary point of the second paired marginal tooth of the

hydrotheca is very small or obsolete. This usually occurs towards the distal ends

of hydrocladia, while the division is well marked towards the proximal ends.

Distribution outside South Africa. Australia, southern Indian Ocean (St. Paul),

west coast of Africa. Type locality: Queenscliff, Australia.

Distribution in South Africa. Very common in littoral region and shallow water

all round the coast from South West Africa to Natal, to a depth of 84 m.

Characteristic of wave-washed areas. 26/15 (1), 29/16 (1), 32/18 (I, s), 33/17 (s),

Ba PS (is), 34/18) s); 33/25 s), 33/270), 32/28 (s), 31/29, s), 31/300),

30/30 (1), 29/31 (1)

Doubtful species

Aglaophenia alopecura Kirchenpauer, 1872

Aglaophenia alopecura Kirchenpauer, 1872: 33, pl. 3 (fig. 10). Marktanner-Turneretscher,

1890: 263, pl. 6 (fig. 20), pl. 7 (fig. 21). Stechow, 1912: 371.

Remarks. Kirchenpauer’s description of this species is not sufficient for recognition,

and unfortunately most of Kirchenpauer’s collection no longer exists. Marktanner-

Turneretscher’s description of material from Algoa Bay would apply equally well to

Thecocarpus flexuosus umbellatus, except that no mention is made of a hydrotheca at

the base of each corbula rib, a feature which can easily be missed. Stechow’s material

(probably South African!) was fragmentary and does not help. It is recommended that

the species be dropped from the records.

Aglaophenia attenuata Allman, 1883

Aglaophenia attenuata Allman, 1883: 37, pl. 11 (figs 7-9).

Remarks. The shape of the hydrotheca in this species resembles that of Thecocarpus

brevirostris and that of Aglaophenia tubulifera. Allman says that’the ‘mesial’ (median

abcauline) tooth of the hydrotheca is bifid, but it is not clear whether he means that

there is an inner and an outer point (as in Aglaophenia latecarinata), or whether the

two points lie side by side.

Although Allman, in his diagrams, does not show hydrothecae at the bases of

the corbula ribs, it is possible that he may have missed this feature.

Billard (1908) was unable to find Allman’s type material in the British Museum.

The position and nature of the species must thus remain doubtful.

Aglaophenia holubi Leloup, 1934

Aglaophenia (?) holubi Leloup, 1934: 4, figs 4-6.

Remarks. This species was created for some admittedly badly preserved material,

which can probably be included in A. pluma. The hydrotheca is missing the most

adcauline pair of the marginal teeth, which is often very poorly developed in A. pluma.

The corbula figured by Leloup would agree with a young corbula of A. pluma in which

the ends of the ribs had been damaged and the gonophores broken off.

416 ANNALS OF THE SOUTH AFRICAN MUSEUM

Aglaophenia pusilla Kirchenpauer, 1872

Aglaophenia pusilla Kirchenpauer, 1872: 32, pl. 1 (fig. 3), pl. 3 (fig. 3). Bedot, 1921: 335.

Stechow, 1923c: 256.

Remarks. The presence of cauline hydrothecae and the toothed margin of the hydro-

theca in this species suggest the genus Gattya (Halopterinae). Yet the presence of seven

marginal teeth, of which the median abcauline is greatly elongated, is characteristic

of no known South African species of the genus. Since Kirchenpauer’s type material

is no longer available the presence of the species in the country must await confirma-

tion and its systematic position remain doubtful.

Aglaophenia tubulifera (Hincks, 1861)

Plumularia cristata: Busk, 1851: 118.

Plumularia tubulifera Hincks, 1861: 256, pl. 7 (figs 1-2).

Aglaophenia tubulifera: Hincks, 1868: 288, pl. 63 (fig. 2). Billard, 1906: 231, figs 20-21. Millard

1961: 206.

Aglaophenia filicula Allman, 1883: 36, pl. 11 (figs 1-6).

Remarks. The only South African record of this species is that of Busk (1851), a

record which was quoted by Hincks (1868) and probably also by Kirchenpauer (1872).

Though Busk’s material appears to belong to this species, the distinction between

A. tubulifera and A. pluma is not clear since both species are very variable, and it

is possible that all South African material should be included in A. pluma.

Genus Cladocarpus Allman, 1874

Syn. Dinotheca Stechow, 1911.

Cladocarpella Bale, 1915.

Aglaophenopsis Fewkes, 1881.

Nematocarpus Broch, 1918.

Diagnosis. Stem branched or unbranched, bearing alternate hydrocladia.

Hydrocladia usually unbranched. Hydrotheca deep, often bent into an S-shape,

with or without intrathecal septa, usually with a median abcauline tooth, with

or without lateral teeth. Nematothecae usually with more than one aperture;

median inferior nematotheca short, usually below hydrotheca, never reaching

thecal margin. Gonothecae protected by phylactocarps which arise as append-

ages of the hydrocladia. Phylactocarps branched or unbranched, usually without

hydrothecae, bearing one or two rows of nematothecae.

Type species: Cladocarpus formosus Allman, 1874.

KEY TO SPECIES*

1. Abcauline wall of hydrotheca not eet an curved and axis of Sa more or

less straight .. 2

— Abcauline wall of hydrotheca markedly convex in 1 lower part and axis ‘of hydrotheca

twisted into an S-shape which may be very pronounced 8 , is >

2. Hydrothecal margin with three teeth, one median abcauline and two Hisel C. lignosus

— Hydrothecal margin with one rete abcauline tooth only 6 .

3. Hydrotheca with two intrathecal septa, one adcauline and one abcauline C. leloupi

— Hydrotheca with no intrathecal septa .. ae ae

4. Depth of hydrotheca 2-3 times marginal Hanes Phylactocarps with short

nematothecae (under 0,1 mm) a aes ps ae a : C. distomus

* See also Addendum, p. 483.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 417

— Depth of hydrotheca 33-5 times aa diameter. eee with long

nematothecae (over 0,4 mm) ie Js = P oe .- C. tenuis

5. Hydrothecal margin untoothed .. ay a C. millardae

— Hydrothecal margin with one median abcauline tooth . a oe me 1 at |

6. Hydrotheca without intrathecal septum .. one ae i es die ate

— Hydrotheca with one intrathecal septum Le $ ts a. Mee

7. Three of the internodal septa carried outwards (to Abodulicie side) oF curvature of

hydrotheca and not reaching opposite (adcauline) side of internode. No horn on

convexity of hydrotheca .. C. inflatus

— All but one or two of the internodal septa ‘carried outwards by curvature of

hydrotheca. Convexity of ns Sede el horn which reaches above level

of thecal margin... 3 re a .. C. dofleini

8. Intrathecal septum Ab cauline 3 50 ee nt ss ag C. valdiviae

— Intrathecal septum adcauline a M3 ov ret ta eo,

9. Basal two-thirds of abcauline wall convex, maximum concavity at aboers eiaet

C. sinuosus

— Basal third of abcauline wall convex, maximum concavity below half height lO

10. Convex part of abcauline wall capped by a horn, adcauline part of margin cut

away .. Bhs ae ae C. unicornus

— Abcauline wall not thickened, margin not cut away ee oe oe C. crepidatus

Cladocarpus crepidatus sp. nov.*

Fig. 130A—C

Holotype. SAM-HS537: Agulhas Bank off Still Bay, 35°22’S/22°31’E, 200 m.

Description. A single stem without rootstock and in two parts, altogether 46 mm

long. The stem bears alternate hydrocladia in the distal two-thirds, although

most of these have been broken off. The longest bear seven hydrothecae and

are 6 mm in length.

Stem fascicled, consisting of a principal hydrocladia-bearing tube and a

number of peripheral tubes applied to its posterior surface. Only the last half

millimetre is unfascicled. Principal tube exposed on anterior surface, without

visible nodes; with many septa in proximal region (4-6 between consecutive

apophyses) which gradually disappear in the distal region. Apophyses short,

directed alternately to right and left. Two cauline nematothecae between con-

secutive apophyses, of which one is seated in the axil and displaced slightly to

that side. Cauline nematotheca sac-shaped, with two terminal apertures.

Hydrocladium bearing up to seven thecate internodes, which are slightly

sigmoidally curved, the first curvature being the stronger; nodes slightly oblique.

Each internode with 9-13 septa, one or two below the hydrotheca, 7-11 behind

it and usually one above it.

Hydrotheca with double curvature: abcauline wall convex basally and

with maximum convexity at about } height; concave above this and with

maximum concavity at about 3 height; then widening evenly to margin; not

thickened in any region. Adcauline wall smoothly convex. Margin with a single

inturned abcauline tooth and sinuous or crenulated lateral edges. A short

* crepidatus (L): wearing sandals or slippers.

418 ANNALS OF THE SOUTH AFRICAN MUSEUM

adcauline intrathecal septum present immediately above hydropore, curved

upwards and projecting into bulging basal part.

Median inferior nematotheca short and free from hydrotheca, with two

apertures, one terminal and one on upper surface. Lateral nematotheca tubular

and overtopping thecal margin; with three apertures, either one terminal and

two mesial or two terminal and one mesial.

Phylactocarps borne on hydrocladia below the first hydrotheca and to one

side, reaching 1,4 mm in length and bearing five pairs of long nematothecae

when mature. Nematothecae about 0,8 mm in length, with two apertures on a

raised process close to the origin, one or two apertures along the length and one

terminal. Both the main axis of the phylactocarp and the nematothecae with

many septa. Each phylactocarp bearing 2-4 gonothecae between the origins of

members of the first to fourth pairs of nematothecae. Gonothecae female,

broad-oval in front view, slipper-shaped in side view with a broad subterminal -

aperture, each containing one planula larva.

Measurements (mm)

Hydrocladium, internode length . as ba a .. 0,80-0,98

Hydrotheca, depth including median tooth vA ty : .. 0,55-0,70

diameter at margin .. x Re ae uh oe .. 0,22-0,25

Gonotheca, length .. = a ee a ae reaching 0,60

maximum diameter .. a a eh ae reaching 0,33

Remarks. The convexity of the basal part of the abcauline thecal wall is typical

of a number of Cladocarpus species with a sigmoidally curved hydrotheca. In

degree of curvature it lies between C. sinuosus Vervoort, 1966 and C. unicornus

sp. NOV.

It differs from C. sinuosus in the larger hydrothecae in which the basal part

of the abcauline wall is more protuberant and the greatest concavity is at a

lower level. The intrathecal septum is also at a lower level.

Distribution. Endemic to South Africa.

Distribution in South Africa. The only record is the holotype recorded above.

35/22 (d)

Cladocarpus distomus Clarke, 1907

Fig. 130D-F

Cladocarpus distomus Clarke, 1907: 17, pl. 14. Stechow, 1925a: 506, fig. 47. Millard, 1967:

188, fig. 6. Millard, 1968: 280. Vervoort, 19665: 150, figs 48-50. Vervoort, 1972: 212,

fig. 73a.

Cladocarpus sibogae: Billard, 1913: 71, figs 57-58, pl. 4 (fig. 39). Billard, 1918: 26, fig. 5.

Cladocarpella multiseptata Bale, 1915: 304: pl. 47 (figs 1-5).

Cladocarpus plumularioides Jarvis, 1922: 352, fig. 3. Vervoort, 19665: 152, fig. 51.

?Cladocarpus bathyzonatus Ritchie, 1911: 861, pl. 89 (figs 2, 6-11). Vervoort, 1966b: 153,

fig. 53.

?Cladocarpus multiapertus Billard, 1913: 73, fig. 59.

?Cladocarpus alatus Jarvis, 1922: 351, fig. 2, pl. 26 (fig. 25). Vervoort, 1966b: 152, fig. 52.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 419

Fig. 130.

Cladocarpus crepidatus sp. nov., from holotype. A, gonotheca and nematotheca from

phylactocarp; B, part of stem in anterior view showing two phylactocarps and their

gonothecae; C, hydrocladium.

Cladocarpus distomus. D, stem; E, hydrocladium; F, hydrocladium with phylactocarps

bearing gonothecae.

Cladocarpus dofleini, redrawn from Vervoort (19665). G, hydrotheca.

Scale: D in cm, the rest in mm/10.

420 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis. Hydrorhiza forming a branching root-stock for penetration of mud.

Stem weakly fascicled at base, unbranched, reaching about 100 mm in height,

bearing alternate hydrocladia from an axial tube. Axial tube with or without

irregular, oblique hinge-joints; with or without indistinct transverse nodes;

without septa; bearing a row of nematothecae on anterior surface, of which

one is seated in the axil of each hydrocladial apophysis.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by slightly oblique nodes. Internodes straight or

curved, with or without septa; with three or four nematothecae, one median

inferior, one pair laterals and sometimes one median superior.

Hydrotheca deep; not sigmoidally curved; abcauline wall smoothly con-

vex or with a slight concavity in distal half; widening to margin; without

intrathecal septum; 0,5-1,0 mm in abcauline height including median tooth,

and 0,2-0,3 mm in marginal diameter; with a delicate adcauline shelf of peri-

sarc overarching the hydropore. Margin perpendicular to hydrocladium, with

one median abcauline tooth.

Median inferior nematotheca seated below hydrotheca and not reaching its

base, with at least two apertures, one terminal in the form of a narrow trans-

verse slit which may be subdivided, and one circular on upper surface near base.

Lateral nematotheca tubular or spreading round lateral wall of hydrotheca

even as far as median tooth; with one to many apertures, the first usually raised

slightly above the level of the rest and overtopping thecal margin. Median

superior nematotheca, when present, seated above hydrotheca, similar to median

inferior. Cauline nematotheca similar to median inferior. Phylactocarps borne

on hydrocladia, several to each, unbranched, with four or five pairs of short

nematothecae (less than 0,1 mm), bearing one to three gonothecae on basal

region. Gonotheca elongate, with terminal, transversely widened aperture.

Nematothecae similar to median inferior.

Variation. This is a very variable species, thus accounting for the many synonyms

under which it is known. Variation occurs in the following features:

(i) Branching. The stem is normally unbranched, but rare examples of branch-

ing have been reported from outside South Africa, and colonies have been

observed where some hydrocladia continue as stems and give off secondary

hydrocladia.

Gi) Stem segmentation. Some stems are completely unsegmented, others have

oblique hinge-joints and/or indistinct transverse nodes. Hinge-joints are

quite irregular in position and may occur in groups of three or four close

together. Transverse nodes generally occur in the distal part of the stem and

are more regular, one above each hydrocladium.

(iii) Number of internodal septa in hydrocladia. This varies from none at all to

as many as 19 to an internode, in which case about 11 are behind the adcauline

wall of the hydrotheca.

(iv) Cauline nematothecae. A variable number occurs between two consecutive

hydrocladia, 2-14 have been reported in the literature and 2-12 observed in

South Africa.

(v) Structure of nematothecae. The typical slit-like terminal aperture lends itself

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 421

to modification, for by widening of the nematotheca and approximation of

the margins the aperture may be subdivided. Thus, the median nematotheca

may have one to four terminal apertures, and the lateral nematotheca may

extend round the lateral margin of the hydrotheca as far as the abcauline

median tooth and have many terminal apertures.

(vi) Median superior nematothecae, which may be present or absent, and if

present may vary in number from one to three. The number appears to be

related to the length of the internode which also is variable. There is never

more than one inferior median nematotheca, but its distance from the base

of the hydrotheca varies.

Distribution outside South Africa. Eastern Pacific, 6°51'N/81°42,5’W, 1012 m

(type locality), East Indies, Queensland, East Africa.

Distribution in South Africa. Off Cape Town, Natal and Mocambique, in 292

to 2 200 m. 34/17 (a), 30/31 (d, vd), 30/32 (a), 29/31 (d, vd), 24/36 (a), 23/37 (a)

Cladocarpus dofleini (Stechow, 1911)

Fig. 130G

Dinotheca dofleini Stechow, 1911: 194, fig. 1. Stechow, 1925a: 508, figs 49-52. Vervoort, 1966b:

162, figs 63-64.

Diagnosis. Hydrorhiza a tuft of branching tubes for penetration of mud. Stem

fascicled, unbranched, reaching a maximum height of 35 mm, bearing alternate

hydrocladia from an axial tube. Axial tube exposed on anterior surface, not

divided into internodes, without septa, bearing a row of nematothecae on

anterior surface, of which there are two to five between two consecutive

hydrocladia including one in the axil of hydrocladial apophysis.

Hydrocladium bearing hydrothecae on upper surface, consisting of slightly

curved and slender thecate internodes separated by oblique nodes. Each inter-

node bearing a hydrotheca in proximal half, with numerous septa of which all

except the first one or two and the last one or two are carried outwards by the

curvature of the hydrotheca and drawn away from the opposite side of the

internode. Each internode with three nematothecae, one median inferior and

one pair laterals.

Hydrotheca laterally compressed and with exaggerated double curvature;

abcauline wall grossly convex basally and bulging outwards and upwards above

thecal margin, this part capped by a pointed spine, concave above this and

widening to margin; adcauline wall deeply but smoothly curved; basal part of

internode carried outwards with the base of the hydrotheca. Hydrotheca with

no intrathecal septum; 0,5-0,6 mm from upper adcauline wall to spine and

0,2 mm in marginal diameter; margin forming an angle of about 45° with

hydrocladium, slightly sinuous, with one median abcauline tooth; hydropore

surrounded by a low collar and a ring of minute teeth. Hydranth with 12-14

tentacles.

Median inferior nematotheca free from hydrotheca and not reaching its

base, with two apertures, one terminal, and one on upper surface. Lateral

422 ANNALS OF THE SOUTH AFRICAN MUSEUM

nematotheca tubular, overtopping thecal margin, with one terminal aperture.

Cauline nematotheca spindle-shaped, with two apertures, one terminal and one

adcauline, containing an intranematothecal ridge.

Phylactocarps (not recorded from South Africa) borne as a pair on first

internode of hydrocladium, unbranched, unsegmented, without hydrothecae,

bearing a double row of nematothecae and one gonotheca between members of

the first pair of nematothecae. Gonotheca lens-shaped with a slit-like terminal

aperture (Stechow).

Variation. The measurements given above are from the South African material

reported by Vervoort, which consisted of young colonies, some of them

unfascicled. Stechow has described an older, fertile colony from East Africa,

with a fascicled stem almost 1 mm thick at the base and 130 mm high.

Stechow reports an S-shaped septum in some of the median inferior

nematothecae, a second aperture for the lateral nematothecae and only one

aperture for the cauline nematothecae. Presumably these are variable characters.

Stechow also reports that in the first hydrotheca of a phylactocarp-bearing

hydrocladium the curvature is less pronounced and the spine absent.

Distribution outside South Africa. Off East Africa. Type locality: probably

Agulhas Bank, South Africa, on a crab.

Distribution in South Africa. Off Durban in 425 to 495 m. 29/31 (d)

Cladocarpus inflatus Vervoort, 1966

Fig. 131H

Cladocarpus infiatus Vervoort, 1966b: 158, figs 58-59.

Diagnosis. Stem delicate, unfascicled, reaching a maximum height of 50 mm,

unbranched, bearing short hydrocladia more or less spirally arranged, not

divided into internodes but containing numerous straight septa, bearing a row

of nematothecae, of which one is seated in the axil of each hydrocladial

apophysis.

Hydrocladium consisting of three to five sigmoidally curved thecate inter-

nodes separated by slightly oblique nodes. Internodes containing numerous

septa, of which three are carried outwards by the curvature of the hydrotheca

and drawn away from the opposite side of the internode. Each internode with

three nematothecae, one median inferior and one pair laterals.

Hydrotheca with double curvature; abcauline wall very strongly convex

basally and with maximum convexity below + height, strongly concave above

this with maximum concavity at about 4 height, then widening evenly to margin,

not thickened; adcauline wall strongly and evenly curved; with no intrathecal

septum; 0,4 mm in height and 0,2 mm in marginal diameter; margin with one

inturned median abcauline tooth and sinuous or crenulated lateral edges.

Median inferior nematotheca free from hydrotheca and well below its base,

with two apertures, one terminal and one on upper surface near base. Lateral

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 423

nematotheca tubular, overtopping thecal margin, with three apertures, one

terminal, one lateral and one mesial. Cauline nematotheca with one terminal

aperture and containing an intranematothecal septum.

Gonotheca unknown.

Distribution. Endemic to South Africa.

Distribution in South Africa. Type locality and only record; off Durban in 495 m.

29/31 (d)

Cladocarpus leloupi Millard, 1962

Fig. 131A—-D

Cladocarpus flexilis Leloup, 1939: 14, fig. 10.

Cladocarpus leloupi Millard, 1962: 304.

Diagnosis. Hydrorhiza forming a branching root-stock for penetration of mud

or attachment to pebbles. Stem fascicled, flexible, reaching a maximum height of

237 mm, usually unbranched, bearing alternate hydrocladia. Axial tube without

internodal septa, divided by oblique nodes (which may be invisible in older

stems) into long internodes, each bearing one hydrocladial apophysis near distal

end and a row of nematothecae on anterior surface.

Hydrocladium bearing hydrothecae on upper surface, consisting of straight

thecate internodes separated by oblique nodes. Internodes containing five to

eight well-marked septa, of which the first is oblique and the remainder trans-

verse. Each internode with three nematothecae, one median inferior and two

lateral.

Hydrotheca vase-shaped, not sigmoidally curved, with axis parallel to

internode; with two intrathecal septa, one adcauline about half-way up and one

abcauline about quarter way up; 0,5-0,6 mm in abcauline height and 0,19-0,3

mm in marginal diameter; margin with one median abcauline tooth.

Median inferior nematotheca seated below hydrotheca and not reaching its

base, bifurcated, with two terminal apertures and one on upper surface near

base. Lateral nematotheca just overtopping thecal margin, usually trifurcated,

with three terminal apertures and one lateral. Cauline nematotheca usually

bifurcated, with two terminal apertures and one on upper surface.

One or two phylactocarps borne on first and sometimes on second inter-

node of hydrocladium, unbranched, segmented, with two nematothecae on

each segment, bearing gonothecae on first two or three segments. Gonotheca

flattened distally and curled over the subterminal transverse aperture.

Variation. The stem occasionally bears one or two long branches. The number

of nematothecae on the cauline internodes varies from three to six. The last

one is always seated in the axil of the hydrocladial apophysis.

The intrathecal septa, so characteristic of the species, tend to disappear

towards the distal ends of young hydrocladia.

The number of terminal apertures in the lateral and cauline nematothecae

is variable (1-4 in the former and 1-3 in the latter).

424 ANNALS OF THE SOUTH AFRICAN MUSEUM

ign isle

Cladocarpus leloupi. A, stem; B, hydrocladium; C, hydrocladium bearing two phylactocarps,

redrawn from Leloup (1939, as C. flexilis); D, anterior view of stem showing origins of

hydrocladia.

Cladocarpus millardae. E, stem; F, phylactocarp bearing male gonothecae; G, hydrocladium.

Cladocarpus inflatus, redrawn from Vervoort (19665). H, hydrotheca.

Scale: A and E in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 425

Distribution. Endemic to South Africa. Type locality: Cape Agulhas.

Distribution in South Africa. Agulhas Bank from Cape Agulhas to East London

in 80 to 120 m. 34/20, 35/21 (d), 34/22 (s), 34/23 (s), 34/25 (s, d), 34/26 (d),

33/27 (s) ;

Cladocarpus lignosus (Kirchenpauer, 1872)

Fig. 132A—D

Aglaophenia lignosa Kirchenpauer, 1872: 28, 37, pl. 1 (fig. 13); pl. 4 (fig. 13).

Cladocarpus lignosus: Stechow, 1919b: 135. Stechow, 1923c: 243, fig. J+. Stechow, 1925a:

505. Millard, 1962: 305, fig. 9.

Diagnosis. Hydrorhiza a hard and thickened mat. Stem thick, strongly fascicled,

very hard and woody, reaching a maximum height of 700 mm, branching

profusely and in one plane, bearing alternate hydrocladia from an axial tube in

the younger parts of the colony. Axial tube, where exposed, divided into regular

internodes by transverse nodes. Each internode without septa, bearing one

hydrocladial apophysis and two nematothecae, one on proximal region and the

other in the axil. Each peripheral tube with two rows of nematothecae.

Hydrocladium bearing hydrothecae on upper surface, consisting of one

short, athecate internode followed by longer straight thecate internodes. All

nodes oblique. Two internodal septa in first internode, three to five in thecate

internodes: three behind the hydrotheca and sometimes one proximal and one

distal. First internode with one median nematotheca, remainder with one

median inferior and one pair laterals.

Hydrotheca vase-shaped, not sigmoidally curved, with axis forming an

angle of 20-30° with hydrocladium, widening slightly to margin, with no

intrathecal septum, 0,2-0,3 mm in height and 0,15-0,19 mm in marginal

diameter. Margin with three teeth, one median abcauline and two lateral.

Median inferior nematotheca seated below hydrotheca and reaching to

just above its base, bifurcated, with two terminal apertures. Lateral nemato-

theca bifurcated, with one mesial and two terminal apertures, one of the latter

overtopping thecal margin and one approximately level with it. Cauline

nematotheca with two terminal openings.

Phylactocarps borne on first internode of hydrocladia, singly or in pairs,

curved, unbranched, indistinctly segmented, bearing one to four gonothecae.

Each ‘segment’ with two nematothecae. Gonotheca elongate, with distal

rectangular aperture.

Variation. The method of branching is very irregular, sometimes alternate,

sometimes opposite and sometimes unilateral, but the general result is usually

a fan-shaped colony.

Distribution. Endemic to South Africa. Type locality: given only as Cape of

Good Hope.

Distribution in South Africa. Fairly common from 10 to 120 m on the Agulhas

426 ANNALS OF THE SOUTH AFRICAN MUSEUM

Bank, reaching Cape Agulhas in the west and Natal in the east. 34/19 (s),

34/20 (s), 34/21 (s), 34/23 (s), 34/24 (d), 33/25 (S), 34/25 (s, d), 33/26 (s, d), 33/27

(s), 32/28 (s), 33/28 (s), 29/31 (s)

Cladocarpus millardae Vervoort, 1966

Fig. 131E-G

Cladocarpus millardae Vervoort, 1966b: 160, figs 60-62.

Diagnosis. Hydrorhiza a branching root-stock for penetration of mud. Stem

fascicled, unbranched, reaching a maximum height of 100 mm, bearing alternate

hydrocladia from the anterior surface of an axial tube. Axial tube exposed on

anterior surface, unsegmented, without septa, bearing a row of nematothecae,

two to four between two successive hydrocladial apophyses, of which one is

seated in the axil of the apophysis.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

sigmoidally curved thecate internodes separated by oblique nodes. Internodes

with two to six incomplete septa, the two strongest behind basal part of

hydrotheca; each with three nematothecae, one median inferior and two

lateral.

Hydrotheca with double curvature; abcauline wall strongly convex basally

and with maximum curvature at 4-4 height; concave above this and with maxi-

mum concavity at about ? height, then widening to margin; adcauline wall

following roughly the same curvature; a strong adcauline intrathecal septum

projecting into bulging basal portion; 0,4-0,6 mm in abcauline depth and 0,2-

0,3 mm in marginal diameter; margin smooth and without teeth.

Median inferior nematotheca seated below hydrotheca, with three or four

tubular apertures. Lateral nematotheca broad and spreading round lateral wall

of hydrotheca almost to abcauline side, with 4-9 apertures. Cauline nemato-

theca triangular, with four apertures, two lateral and two medial, with

intranematothecal septum.

Phylactocarp borne on first or second internode of hydrocladium, slightly

curved, unbranched, segmented at least in distal part, with two nematothecae

on each segment, bearing gonothecae on the first one or two segments.

Gonotheca globular, with truncated distal end and subterminal aperture.

Variation. The position of the inedian inferior nematotheca relative to the

hydrotheca varies. In the proximal part of the colony it is immediately below

the hydrotheca, but in the distal part it is separated from the hydrotheca by a

distance approximately equal to its own length.

Distribution outside South Africa. North of Madagascar. Type locality: off

Mocambique (25°20'S/35°17’E) in 575 to 595 m.

Distribution in South Africa. Still Bay on the south coast to Mocambique, from

200 to 595 m. 35/22 (d), 29/31 (d), 25/35 (wd)

427

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

N aN

SSS \)

= SE = Sram Saar Ss

J Ss a OO tl

: > “ye

=) On.

g origins of hydrocladia;

g gonothecae.

young phylactocarp bearing a gonotheca; F, stem; G, anterior

stem; B, anterior view of stem showin

hydrocladium with phylactocarp bearin

Scale: A and F in cm, the rest in mm/10.

wa SAN y <a «,

BY) Heels CK pa

Y "

RAK

view of stem showing young phylactocarps and origins of hydrocladia; H, hydrocladium.

C, hydrocladium; D,

Cladocarpus lignosus. A

Cladocarpus sinuosus. E,

428 ANNALS OF THE SOUTH AFRICAN MUSEUM

Cladocarpus sinuosus Vervoort, 1966

Fig. 132E-H

Cladocarpus sinuosus Vervoort, 19665: 155, figs 55-57.

Diagnosis. Hydrorhiza a tuft of fibres or a flat mat. Stem fascicled or unfascicled,

unbranched, reaching a maximum height of 53 mm, bearing hydrocladia on

anterior surface directed alternately to left and right, not divided into inter-

nodes, without septa, bearing a row of nematothecae on anterior surface, of

which there is one in the axil of each hydrocladial apophysis.

Hydrocladium consisting of sigmoidally curved thecate internodes separated

by straight or oblique nodes. Internodes containing septa, with three nemato-

thecae, one median inferior and one pair laterals.

Hydrotheca with double curvature; abcauline wall convex basally and

with maximum convexity at about 4 height, concave above this and with

maximum concavity at about ¢ height, then widening to margin; adcauline wall

following roughly the same curvature; an adcauline intrathecal septum at about

+ height projecting into bulging basal part; 0,3-0,5 mm in abcauline height and

0,13-0,2 mm in marginal diameter; margin with one median abcauline tooth

and faintly sinuous lateral edges.

Median inferior nematotheca seated below hydrotheca and more or less

reaching to its base, with two apertures, one terminal and one on upper surface

near base. Lateral nematotheca tubular, overtopping thecal margin, with two

apertures, one terminal and one mesial, with an intranematothecal septum.

Cauline nematotheca spindle-shaped, with two apertures, one terminal and one

on upper surface, with an intranematothecal septum.

Phylactocarp borne on first internode of hydrocladium, curved, unbranched,

segmented, with two very long, curved nematothecae on each segment. Nemato-

theca with up to four apertures, one terminal and the rest on the distal surface.

Gonothecae borne below first pair of nematothecae, ovoid with truncated

distal end, reaching 0,4 mm in length and 0,3 mm in maximum diameter

(young).

Variation. This rare species is known only from a few stems. From these it is

evident that there is variation in

(i) The number of cauline nematothecae between two successive hydrocladia

(1-5).

(ii) The number of septa in the hydrocladial internodes (3-8). There are one or

two below the hydrotheca, 2—5 behind it and sometimes one above it.

(iii) The length of the hydrocladial internodes, particularly the distal part where

evidence of regeneration may be present.

(iv) The size of the hydrotheca and the amount of curvature.

(v) The occasional absence of the abcauline marginal tooth of the hydrotheca.

Vervoort has established a separate variety edentatus for the form without a

marginal thecal tooth and with a slender hydrotheca.

Distribution. Endemic to South Africa.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 429

Distribution in South Africa. Off Durban (type locality) and on the Agulhas Bank,

in 183 to 550 m: 35/22 (d, vd), 34/23 (d), 29/31 (d), 27/32 (d)

Cladocarpus tenuis Clarke, 1879

Fig. 133D

Cladocarpus tenuis Clarke, 1879: 247, pl. 5 (figs 31, 31b). Vervoort, 19665: 154, fig. 54.

Diagnosis. Stem unfascicled, unbranched, reaching 40 mm in height, bearing

alternate hydrocladia, containing some oblique nodes in basal region only,

bearing a row of nematothecae on anterior surface, of which one is seated in the

axil of each apophysis.

Hydrocladium consisting of weakly sigmoidal thecate internodes separated

by slightly oblique nodes. Internodes containing numerous septa and bearing

three nematothecae, one median inferior and two laterals.

Hydrotheca very deep and slender, not sigmoidally curved, narrowest in

centre, then widening to margin; abcauline wall slightly concave in centre;

adcauline wall straight; without intrathecal septum, 0,7—-0,9 mm in height (with-

out median tooth) and 0,19-0,2 mm in marginal diameter; margin with one

median abcauline tooth and crenulated lateral edges.

Median inferior nematotheca free from hydrotheca, short and not reaching

thecal base, with large, fan-shaped terminal aperture. Lateral nematotheca

tubular, overtopping thecal margin, with terminal aperture. Cauline nematotheca

similar to median inferior.

Phylactocarp borne on first internode of hydrocladium, unbranched,

segmented, with two long nematothecae (over 0,4 mm) on each internode.

Gonothecae unknown. Nematotheca with three apertures, one terminal and

two lateral.

Variation. The number of cauline nematothecae between two successive

hydrocladial apophyses varies from three to ten.

Distribution outside South Africa. Gulf of Mexico, 185 m (type locality), Virgin

Islands, West Indies.

Distribution in South Africa. Off Durban in 495 m. 29/31 (d)

Cladocarpus unicornus sp. nov.

Fig. 133E-F

Holotype. SAM-H538: off Mocgambique, 24°46’S/35°18’E, 110 m.

Description. A single stem in two parts, together 52 mm long. The stem bears

alternate hydrocladia, but most of these, and all those in the basal region, have

been broken off short. The longest are 6,5 mm in length and bear seven hydro-

thecae. At the base of the stem the component tubes separate from one another

in such a way as to suggest that this is the beginning of the rootstock and the

base of the colony.

430 ANNALS OF THE SOUTH AFRICAN MUSEUM

Stem fascicled, consisting of a principal hydrocladia-bearing tube and a

number of peripheral tubes applied to its posterior surface. The peripheral

tubes terminate one by one until the distal part of the stem remains unfascicled.

In no place is the anterior surface of the principal tube and its hydrocladia-

bearing apophyses covered by peripheral tubes..Principal tube with no visible

nodes, but with many septa (varying in number from four to ten between two

consecutive apophyses, but usually five or six). Apophyses short, each con-

taining one septum, directed alternately to the right and the left. A row of

cauline nematothecae present on the anterior surface of the principal tube,

2-4 (usually two) between two consecutive apophyses. Of these one is always

axillary and displaced to the corresponding side. Cauline nematotheca with

two or three apertures, one or two terminal and one on upper surface.

Hydrocladia bearing up to seven straight thecate internodes separated by

slightly oblique nodes. Each internode containing 8-12 septa, usually two below

the hydrotheca, six or seven behind it and two above it.

Hydrotheca with double curvature: abcauline wall strongly convex basally

and with maximum convexity at about + height, this part capped by a short

solid horn of perisarc; strongly concave and indented above this, with maximum

concavity at about # height; then widening evenly to margin. Adcauline wall

strongly convex in basal 3, the convexity decreasing gradually beyond this.

Margin with a single inturned abcauline tooth and the lateral edges cut away

where they approach the internode. A strong adcauline intrathecal septum

present, curved upwards and projecting into bulging basal portion.

Median inferior nematotheca short and free from hydrotheca, with two

apertures, one terminal and one on upper surface near base. Lateral nemato-

theca tubular and overtopping thecal margin; with three apertures, one termi-

nal, one in centre of lateral surface, and one on mesial surface near base.

Phylactocarps absent, though scars for their attachment present on some

hydrocladia immediately below the first hydrotheca.

Measurements (mm)

Distance between two consecutive hydrocladia mst ape .. 0,51-0,69

Hydrocladium, internode length .. a ae ne a .. 0,78-0,98

Hydrotheca, depth including median tooth ae ce ¥! .. 0,61-0,68

diameter at margin .. ee an de a: ve .. 0,23-0,28

Remarks. In the degree of convexity of the basal part of the hydrotheca

C. unicornus lies between C. crepidatus sp. nov. and C. inflatus Vervoort, 1966.

It differs from C. crepidatus in its straight hydrocladial internodes, in the

cut-away adcauline edges of the hydrotheca and in the presence of a horn on

the abcauline thecal wall.

In C. inflatus the curvature of the hydrotheca has involved three of the

internodal septa, which have been drawn away from the opposite side of the

hydrocladium. This has not occurred in C. unicornus.

Distribution. Endemic to South Africa.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 431

Fig. 133.

Cladocarpus valdiviae. A, hydrocladium; B, anterior view of stem showing phylactocarps;

C, male gonotheca and nematotheca from phylactocarp.

Cladocarpus tenuis, redrawn from Vervoort (19665). C-, “ydrocladium and phylactocarp.

Cladocarpus unicornus sp. nov., from holotype. E, anterior view of stem showing origins of

hydrocladia; F, hydrocladium.

Scale in mm/10.

432 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution in South Africa. The only record is the holotype recorded above.

24/35 (d)

Cladocarpus valdiviae Stechow, 1923

Fig. 133A-C

Cladocarpus (?) valdiviae Stechow, 1923b: 116. Stechow, $925a: 507, fig. 48.

Diagnosis. Stem fascicled, unbranched, reaching a height of 39 mm, bearing

alternate hydrocladia from the anterior surface of an axial tube. Axial tube

unsegmented, bearing two, or occasionally three, nematothecae between two

successive hydrocladia, one of which is seated in the axil of the hydrocladial

apophysis.

Hydrocladium consisting of up to 14 thecate internodes separated by

slightly oblique nodes. Internodes straight, containing four or five septa, one

below hydrotheca and three or four behind it; with thick perisarc; each with

three nematothecae, one median inferior and one pair laterals.

Hydrotheca tubular, with triple curvature; abcauline wall convex in basal

part, concave in central part and with maximum concavity below half height,

convex above this; adcauline wall with similar curvature but less pronounced;

an abcauline intrathecal septum arising from indentation in abcauline wall and

projecting half-way across cavity; 0,3-0,4 mm in height and 0,10—0,13 mm in

marginal diameter; margin with one straight median abcauline tooth.

Median inferior nematotheca free from hydrotheca, short and not reaching

thecal base, with two apertures, one terminal and one on upper surface near

base. Lateral nematotheca tubular, overtopping thecal margin, with two aper-

tures, one terminal and one mesial. Cauline nematothecae tubular to triangular.

Phylactocarps borne in a double row on front of stem, one on the first

internode of each hydrocladium, unbranched, curved over towards centre,

unsegmented, with 3-5 pairs of long nematothecae and a varying number of

septa, bearing gonothecae on concave surface. Nematothecae with two aper-

tures, one distal and one lateral. Gonotheca (only male known) curved-oval,

with subterminal circular aperture.

Distribution. Endemic to South Africa.

Distribution in South Africa. Agulhas Bank off Mossel Bay in 155-200 m.

(This species has been rediscovered as a fertile colony from practically the

same position as the type locality.) 35/22 (d)

Genus Gymnangium Hincks, 1874

Syn. Halicornaria Allman, 1874.

Diagnosis. Stem branched or unbranched, bearing pinnately arranged hydro-

cladia. Hydrocladia unbranched. Hydrotheca cup- or flask-shaped, with or

without an intrathecal septum, usually with a toothed margin. Nematothecae

usually with more than one aperture; median inferior adnate to abcauline

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 433

thecal wall, often very long and overtopping thecal margin. Gonothecae unpro-

tected in any way, usually borne on the hydrocladia or their apophyses, which

are unmodified.

Type species: Aglaophenia pennatula Hincks, 1868 (nec. auct.)

(= Halicornaria montagui Billard, 1912)

KEY TO SPECIES

1. Stem fascicled and branched. Hydrocladia usually with internodal septa. Hydrotheca

with untoothed margin and an adcauline intrathecal septum .. : G. gracilicaule

— Stem unfascicled. Hydrocladia without internodal septa. Hydrotheca without ad-

cauline intrathecal septum .. ae nf irs A 2 Man wD

2. Hydrotheca with abcauline iatheeal seatun 3

— Hydrotheca with no intrathecal septum ” Ss eae Js)

3. Median inferior nematotheca short, seldom denapeing Rydt otters “a eG HIGUS

— Median inferior nematotheca long, about twice length of hydrotheca Bs, se OF

4. Median inferior nematotheca tubular, with two openings, one just above thecal

margin, one on summit ae : G. allmanii

Median inferior nematotheca eufter-shaped: opening ‘along. entire upper surface

G. montagui

5. Median inferior nematotheca trifid, with three terminal openings oe .. G. ferlusi

— Median inferior nematotheca with one terminal point or opening ae me aay, 6

6. Median inferior nematotheca short, never reaching thecal margin at G. exsertum

— Median inferior nematotheca long, overtopping thecal margin, at least in some part of

hydrocladium Ce aa ae Ae

7. Hydrotheca with a pronounced aediani adcauiline ceil teoth fF G. arcuatum

— Hydrotheca without median adcauline marginal tooth .. pi : a Ame 8

8. Lateral thecal teeth low and rounded. Median inferior ReeA eos gently curved

with free part forming an angle of 40—50° with internode ; G. africanum

— Lateral thecal teeth longer than wide. Median inferior nematotheca markedly bent,

with free part parallel with internode a a a Bt - G. longirostre

Gymnangium africanum (Millard, 1958)

Fig. 134A—-E

Halicornaria africana Millard, 1958: 215, fig. 1SA—C. Millard, 1968: 280, fig. 6A.

Gymnangium africanum: Millard, 1973: 25, fig. 2A—B.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 165

mm, bearing opposite or subopposite hydrocladia, divided into internodes by

transverse nodes. Internodes without septa, bearing two hydrocladial apophyses

and six nematothecae, three to each apophysis, one on anterior surface below

apophysis, one axillary anterior and one axillary posterior.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by slightly oblique nodes. Internodes without

septa.

Hydrotheca flask-shaped, widening to margin, without intrathecal septum,

0,2-0,3 mm in height and 0,16—0,19 mm in marginal diameter. Margin forming

an angle of 40-60° with internode, with seven marginal teeth, one sharp abcau-

line and three pairs low laterals of which the most adcauline is the smallest.

Hydropore surrounded by small spines.

434 ANNALS OF THE SOUTH AFRICAN MUSEUM

Median inferior nematotheca long, adnate to abcauline thecal wall and

continued beyond it for about the same distance; free part curved gently

distalwards and tapering to a point which may be open or closed; with a second

aperture on upper surface at beginning of free part; no opening into hydrotheca.

Lateral nematotheca saccular, not reaching thecal margin, with one broad

terminal aperture. Cauline nematotheca similar to lateral.

Gonothecae unknown.

Variation. The lower part of the stem is devoid of hydrocladia, irregularly

segmented and bears scattered nematothecae.

Variation occurs in the marginal thecal teeth, which may be ‘smoothed

out’ and indistinct, particularly towards the base of the hydrocladium.

The corner of the lateral nematotheca may be raised into a short tubular

structure, thus forming two apertures, particularly towards the tip of a

hydrocladium and on the stem.

An epizootic form occurs, in which solitary hydrocladia arise direct from

an epizootic hydrorhiza. The internodes are more slender, the marginal thecal

teeth indistinct, and the median inferior nematothecae very strongly reduced

so that they do not reach the margin of the hydrotheca. The latter character

is always more extreme towards the base of the hydrocladium.

Distribution. Endemic to South Africa.

Distribution in South Africa. Natal in 27 to 91 m. Type locality: 28°28’S/

32 25,8 E- 30/3 G); 28/3256)

Gymnangium allmanii (Marktanner-Turneretscher, 1890)

Fig. 134J-K

Halicornaria plumosa Allman, 1883: 52, pl. 18.

Halicornaria allmanii Marktanner-Turneretscher, 1890: 277 (name only, for material see

G. montagui).

Halicornaria allmani: Billard, 1910: 45, fig. 20. Billard, 1912: 474, fig. 7. Jaderholm, 19235:

5, fig. Millard, 1968: 282, fig. 6C.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 99

mm, bearing alternate hydrocladia, divided into internodes by straight nodes.

Internodes without septa, bearing hydrocladial apophyses with three nema-

tothecae, one inferior anterior, one posterior axillary and one anterior axillary.

The two rows of hydrocladia more or less in one plane.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by straight or slightly oblique nodes. Internodes

without septa.

Hydrotheca cup-shaped, with convex adcauline wall and more or less

straight abcauline wall, with an abcauline intrathecal septum reaching about

half-way across, 0,16-0,20 mm in height and 0,11—0,14 mm in marginal diameter.

Margin facing outwards and forming an angle of 20-30° with internode; with a

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 435

A.B,G.H

(Cy

EERE

Fig. 134.

Gymnangium africanum. A and B, distal and proximal ends of hydrocladium; C, stem;

D, anterior view of stem showing origins of hydrocladia (gonothecal scars shaded);

E, hydrocladium of epizootic form.

Gymnangium montagui. F, hydrotheca, redrawn from Marktanner-Turneretscher (1890, as

Halicornaria allmanii var.).

Gymnangium hians. G and H, hydrothecae from distal and proximal ends of hydrocladium.

Gymnangium allmanii. J and K, hydrothecae from distal and proximal ends of hydrociadium.

Scale: C in cm, the rest in mm/10.

436 ANNALS OF THE SOUTH AFRICAN MUSEUM

distinct but low triangular lateral tooth on each side and adcauline to it a bay

of varying depth; no median teeth.

Median inferior nematotheca long, tubular, adnate to abcauline thecal

wall and continued beyond it for about the same distance; free part curved

distally; with two apertures, one terminal and one on upper surface at beginning

of free part, no opening into hydrotheca. Lateral nematotheca pear-shaped,

not reaching thecal margin, with one or more apertures. Cauline nematotheca

broad, with two or three terminal apertures.

Gonothecae borne on hydrocladial apophyses and forming a double row

on front of stem, sac-shaped and truncated distally.

Variation. The most variable feature is the hydrothecal margin. In the South

African material the lateral tooth has a straight or oblique posterior edge and

the bay behind it is shallow. In material from other regions, however, the bay is

deeper and may be recessed below the lateral tooth. The bay is also said to be

more pronounced towards the base of a hydrocladium (Billard 1912).

The lateral nematotheca is of variable structure. In addition to the terminal

aperture with a tubular neck, there is a sac-like projection over the thecal

wall which may have one to several apertures.

There may be two hydrocladia to an internode in the lower part of the

stem and one in the upper part.

Distribution outside South Africa. Off Brazil in 59 m (type locality), Marshall

Islands (Pacific).

Distribution in South Africa. Natal and Mocambique in 42 to 64 m. 29/31 (s),

25/33 (s), 28/32 (s)

Gymnangium arcuatum (Lamouroux, 1816)

Fig. 135A—F

Aglaophenia Arcuata Lamouroux, 1816: 167, pl. 4 (fig. 4).

Halicornaria cornuta Allman, 1886: 153, pl. 23 (figs 1-4).

Halicornaria arcuata: Billard, 1907a: 366, fig. 13. Bale, 1913: 141, pl. 13 (figs 1-4). Millard,

1958: 218, fig. 15D-r. Millard, 1962: 307, fig. 1OA-E. Redier, 1967: 403.

Gymnangium arcuatum: Millard 1973: 23, fig. 1.

Diagnosis. Stem unfascicled, usually unbranched, reaching a maximum height

of 128 mm, bearing alternate hydrocladia, divided into short, broad internodes

by oblique nodes. Each internode without septa, bearing one hydrocladial

apophysis and three nematothecae adjacent to apophysis, two on anterior surface

and one on posterior surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by slightly oblique nodes. Internodes without

septa.

Hydrotheca flask-shaped, widening to margin, without true intrathecal

septum, 0,19-0,3 mm in abcauline height and 0,12—0,19 mm in marginal dia-

meter, with a small abcauline projection overarching hydropore and bearing

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 437

two or three minute denticles. Margin forming an angle of approximately 50°

with internode; with six or eight marginal teeth, one incurved adcauline, one

incurved abcauline and two or three pairs low, rounded laterals.

Median inferior nematotheca long, adnate to abcauline thecal wall and

continued beyond it usually for about the same distance; curved distalwards;

with free part compressed laterally and tapering distally to a point, which may

be open or closed; with a second aperture on upper surface at base of free part;

no opening into hydrotheca. Lateral nematotheca sac-shaped, reaching approxi-

mately to thecal margin, with two terminal apertures, of which one may be

prolonged into a tube or a long, closed spine. Cauline nematothecae similar

to laterals, with two or three apertures.

Gonothecae borne on hydrocladial apophyses, one to each, and forming

a double row on anterior surface of stem, spherical to oval and truncated

distally.

Variation. South African material is so far all unbranched, but the type material

branched several times ‘dichotomously’, and Billard (1907a) reports branching

stems from Madagascar. Branching hydrocladia have been observed once,

probably the result of injury.

In the hydrotheca the shape and number of the lateral marginal teeth vary.

There may be two or three pairs. In the latter case the middle tooth may be the

smallest, which is usually the case in the distal regions of the hydrocladia, or

the most adcauline tooth may be poorly defined, which is usually the case in

the proximal regions of the hydrocladia.

In the nematothecae the length of the free part of the median inferior is

very variable, even in the same stem. The production of one of the apertures of

the lateral nematotheca into a tube or spine usually occurs in the distal regions

of the hydrocladia.

An epizootic form of the species occurs growing on the stems of other

hydroids (Thecocarpus formosus) or on the stem of the normal form (var.

epizootica Millard, 1958; subsp. epizootica: Millard, 1962). This consists of

solitary hydrocladia arising directly from the epizootic hydrorhiza, and, occa-

sionally, stunted stems bearing hydrocladia. In the latter some of the hydrothecae

may be normal, at any rate on the terminal parts of the hydrocladia, but on the

proximal parts of the hydrocladia and in all solitary hydrocladia the hydrothecae

and their nematothecae are stunted, this process becoming more marked towards

the base of the colony. The stunting involves

(a) the hydrocladial internodes which are more slender and delicately formed,

(6) the hydrothecae, which are smaller, as little as 0,11 mm in depth and 0,11 mm

in marginal diameter,

tion of the median abcauline tooth which remains normal,

(d) the median inferior nematotheca, which no longer reaches the margin of the

hydrotheca, so that the free portion with its aperture is missing,

(e) the lateral nematotheca, which is smaller and usually has only one aperture.

438 ANNALS OF THE SOUTH AFRICAN MUSEUM

Rarely the solitary hydrocladia consist of only one internode each, this

occurs when the hydrorhiza extends along the hydrocladia of the host.

Distribution outside South Africa. Sea of Antilles (type locality), Algiers,

Madagascar.

Distribution in South Africa. South West Africa (exact locality not recorded),

Agulhas Bank to Natal, littoral to 55 m. 34/21 (s), 34/22 (s), 34/23 (s), 33/25

(s), 33/27 (Ss), 33/28-(s), 32/28 (s), 31/29 G, s),; 30/30°G), 730/315 29/3 es)

28/32 (s)

Gymnangium exsertum (Millard, 1962)

Fig. 135G-L

Halicornaria exserta Millard, 1962: 309, fig. 11A—H.

Gymnangium exsertum: Millard, 1973: 25, fig. 2C—D.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 83 mm,

bearing alternate hydrocladia, divided into short, broad internodes by slightly

oblique nodes. Internodes without septa, bearing one hydrocladial apophysis

and three nematothecae, one anterior inferior, one axillary anterior and one

axillary posterior.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by transverse nodes. Internodes without septa.

Hydrotheca flask-shaped, widening to margin, with axis curved outwards

and abcauline wall concave in lower part, adnate for over # adcauline length,

then free, without intrathecal septum, 0,3-0,4 mm in abcauline height and 0,2—

0,3 mm in marginal diameter. Margin forming an angle of approximately 60°

with internode, with eight marginal teeth, one low, rounded adcauline, one

narrow abcauline and three pairs laterals.

Median inferior nematotheca short, adnate to abcauline thecal wall and

reaching to about one-third of its height, with one terminal aperture; no open-

ing into hydrotheca. Lateral nematotheca ovoid, not reaching thecal margin,

with one broad terminal aperture. Cauline nematothecae similar to lateral.

Gonothecae borne on hydrocladial apophyses, one to each, and forming

a double row on anterior surface of stem, bowl-shaped and truncated distally.

Variation. The proximal part of the stem may be devoid of hydrocladia and

nematothecae and unsegmented. Beyond this may occur a short region with

irregular segmentation bearing one or two nematothecae to each segment,

before the hydrocladia-bearing part starts.

An epizootic form of the species occurs growing on the stems of other

hydroids (Thecocarpus flexuosus), consisting of solitary hydrocladia arising

directly from the epizootic hydrorhiza and stunted stems bearing a few short

hydrocladia (subsp. epizootica Millard, 1962). The hydrocladial internodes are

longer and narrower than in the normal form and the hydrotheca smaller and

with the axis not so strongly bent outwards. The nematothecae are all smaller,

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 439

Figs 135:

Gymnangium arcuatum. A, fertile stem; B and C, hydrothecae from distal and proximal ends of

hydrocladium; D, anterior view of stem showing origins of hydrocladia; E, male gono-

theca; F, hydrothecae of epizootic form.

Gymnangium exsertum. G, stem; H, gonotheca; J, anterior view of stem showing scars for

gonothecae (shaded) and origins of hydrocladia; K, hydrocladium; L, hydrocladium of

epizootic form.

Scale: A and G in cm, the rest in mm/10.

440 ANNALS OF THE SOUTH AFRICAN MUSEUM

especially in the proximal regions of solitary hydrocladia where the median

inferior may not reach to the base of the hydrotheca.

Distribution. Endemic to South Africa.

Distribution in South Africa. Agulhas Bank, 50 to 115 m. Type locality: 33°49’S/

25°56’E, depth unknown. 33/25, 34/25 (s), 34/25 (d), 32/28 (s)

Gymnangium ferlusi (Billard, 1901)

Fig. 137A—C

Halicornaria ferlusi Billard, 1901: 121, figs 3-4. Billard, 1907a: 370, fig. 14, pl. 25 (fig. 8).

Millard, 1962: 312.

Halicornaria ferlusi var. brevis Jarvis, 1922: 354, fig. 5, pl. 26 (fig. 27).

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of

148 mm, bearing alternate hydrocladia, divided into internodes by oblique nodes

which slope alternately to left and right. Internodes without septa, bearing

one hydrocladial apophysis and three nematothecae, one anterior inferior, one

axillary anterior and one axillary posterior. Mamelon present on upper surface

of apophysis.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by slightly oblique nodes. Internodes without septa.

Hydrotheca flask-shaped, widening to margin, without intrathecal septum,

0,2-0,3 mm in abcauline height and 0,15-0,19 mm in marginal diameter.

Margin forming an angle of approximately 50° with internode; with five mar-

ginal teeth, one abcauline and two pairs laterals of which the more adcauline

is small and sharp and the more abcauline broad and low; adcauline edge

indented in centre.

Median inferior nematotheca long, adnate to abcauline thecal wall and

continued beyond it for the same distance or less, free part curved distally,

trifid, with three terminal apertures of which the centre one is higher than

the others; with an additional aperture on upper surface at beginning of free

part; no opening into hydrotheca. Lateral nematotheca kidney-shaped, not

reaching thecal margin, with 3-4 apertures. Cauline nematotheca similar to

lateral, with 3—5 apertures.

Gonothecae borne on hydrocladial apophyses, one to each, and forming

a double row on anterior surface of stem, ovoid, truncated distally when

mature.

Variation. Jarvis reports a variety from East Africa in which the median inferior

nematothecae are much shorter, reaching to only just above the thecal margin.

Distribution outside South Africa. Fort Dauphin in Madagascar (type locality),

Wasin in East Africa.

Distribution in South Africa. East coast of Cape Province and Natal in 27 to

48 m. 31/29 (s), 30/30 (s), 28/32 (s)

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 441

Gymnangium gracilicaule (Jaderholm, 1903)

Fig. 136

Lytocarpus gracilicaulis Jaderholm, 1903: 299, pl. 14 (figs 3-4).

Halicornaria gracilicaulis: Billard, 1913: 63. Jaderholm, 1920: 9, pl. 2 (fig. 9).

Diagnosis. Hydrorhiza attached to hard objects or forming a branched rootstock

for penetration of the substratum. Stem fascicled, bearing alternate branches

which may redivide in the same way giving up to four orders; all branching in

one plane. Stem and branches bearing alternate hydrocladia from an axial

tube, which is always exposed on anterior face. Axial tube of branch arising

from peripheral tube of stem, in smaller branches divided into regular inter-

nodes by oblique nodes; segmentation invisible in larger branches. Internodes

without septa, bearing one hydrocladial apophysis and two nematothecae,

one anterior inferior and one anterior axillary. Peripheral tubes bearing one or

more longitudinal rows of nematothecae.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by transverse or slightly oblique nodes. Internodes

usually curved, with or without septa.

Hydrotheca deep, sigmoidally curved, not obviously widening to margin;

0,2-0,5 mm in total height and 0,09-0,16 mm in marginal diameter; abcauline

wall convex in lower part, concave in upper part and with a perisarcal thickening

below margin; containing a short adcauline intrathecal septum immediately

above hydropore. Margin facing away from internode; without definite teeth,

smooth, sinuated, or with a low triangular lobe on each side.

Median inferior nematotheca adnate to abcauline thecal wall to just above

level of intrathecal septum, then free and divergent; with two apertures, one

terminal and one on upper surface at beginning of free part; with an additional

opening into hydrotheca near top of adnate part. Lateral nematotheca tubular,

overtopping thecal margin, with two apertures, one terminal and one mesial.

Cauline nematotheca pear-shaped, with two apertures, one terminal and one

adcauline.

Gonothecae borne on hydrocladial apophyses, flattened. Male, when mature

(not recorded from South Africa), with two distal horns of unequal size sub-

tending a terminal aperture. Female truncated distally and containing one egg.

Variation. The basal part of a branch is unsegmented and devoid of hydrocladia

though it bears a row of nematothecae. This part may or may not be separated

from the distal hydrocladium-bearing part by a hinge-joint.

The length of the free part of the median inferior nematotheca is variable

and on this character Billard (1913) established a var. armata for a form with

very long nematothecae (0,38 mm) from the Dutch East Indies. In South

African material the length of the free part varies from 0,02 to 0,22 mm.

Variation in the degree of branching and general appearance of the colony

has Jed to the separation of two subspecies in the South African material

(Millard 1968).

442 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 136.

Gymnangium gracilicaule gracilicaule. A, stem; D, hydrocladium.

Gymnangium gracilicaule lignosum. B, stem; C, anterior view of stem showing gonothecae

and origins of hydrocladia; E, hydrocladium.

Scale: A and B in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 443

Distribution outside South Africa. Tropical and subtropical waters from the

western Pacific through the Indian Ocean to the Red Sea, Suez and east coast

of Africa. Type locality: China Sea, 27°35 'N/123°35’E in 91 m.

Distribution in South Africa. Natal and Mogambique in 42 to 350 m, with

one record from off Cape Town. There is no essential difference in the distribu-

tion of the two subspecies, except that G. g. gracilicaule seems to penetrate to

greater depths (to 350m) than G. g. lignosum (to 100 m). 33/18, 30/30 (s), 29/31

(d), 28/32 (s, d), 26/32, 25/33 (Ss), 24/35°{s), 21/35

KEY TO SUBSPECIES

1. Stem flexuous. Internodal septa of hydrocladium poorly developed, not more than

two ea: ic ar ae oe & bss ~ i .. G.g. gracilicaule

— Stem stiff. Internodal septa of hydrocladium well developed, more than two G. g. lignosum

Gymnangium gracilicaule gracilicaule (Jaderholm, 1903)

Fig. 136A, D

Halicornaria gracilicaulis: Millard, 1967: 191. Vervoort, 1967: 47, figs 14-15.

Halicornia gracilicaulis gracilicaulis: Millard, 1968: 282.

Diagnosis. Stem lightly fascicled, flexible, reaching 171 mm, with two orders of

branching only (i.e. stem bearing alternate branches which bear hydrocladia).

Branches unfascicled, flexible. Hydrocladial internodes slender and long, with

internodal septa poorly developed or absent. Hydrotheca deep and slender

(0,3-0,5 mm in total height), sigmoidal curvature not pronounced and margin

usually forming an angle of 45° or more with internode, with an interval of at

least 0,1 mm between abcauline margin and point of separation of median

inferior nematotheca from hydrotheca.

Gymnangium gracilicaule lignosum (Millard, 1968)

Fig. 136B-C, E

ee gracilicaulis: Billard, 1907a (pp): 364, fig. 12, pl. 25 (fig. 7). Millard, 1958: 219,

. 1SI-J.

Fon eee gracilicaulis lignosa Millard, 1968: 282.

Diagnosis. Stem strongly fascicled and woody, rigid, reaching 205 mm in height,

with up to four orders of branching. Branches fascicled or unfascicled, rigid.

Hydrocladial internodes short and well-marked, with up to six well-developed

internodal septa. Hydrotheca comparatively short (0,2-0,3 mm in total height),

sigmoidal curvature pronounced and margin forming an angle of less than 45°

with internode, with a distance of about 0,05 mm between abcauline margin and

point of separation of median inferior nematotheca from hydrotheca. Perisarc

strongly developed and thickening in abcauline thecal wall very conspicuous.

444 ANNALS OF THE SOUTH AFRICAN MUSEUM

Gymnangium hians (Busk, 1852)

Fig. 134G—H

Plumularia hians Busk, 1852: 396.

Halicornaria hians: Billard, 1913: 68, fig. 56. Vervoort, 1941: 222, figs 7-8. Millard, 1958:

219, fig. 1SG—H. Pennycuick, 1959: 186.

Halicornaria hians var. profunda: Ritchie, 1910a: 24, pl. 4 (figs 13-14).

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 9 mm,

bearing alternate hydrocladia, divided into internodes by straight nodes.

Internodes without septa, bearing one or two hydrocladial apophyses and three

nematothecae to each apophysis, one anterior inferior, one axillary anterior and

one axillary posterior.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by straight or slightly oblique nodes. Internodes

without septa.

Hydrotheca cup-shaped, with convex adcauline wall and indented abcauline

wall; with an abcauline intrathecal septum reaching about half-way across, the

edge of which is thickened, upturned and denticulate, 0,13-0,3 mm in height

and 0,16-0,2 mm in marginal diameter. Margin facing outwards and forming

an angle of 20-40° with internode, with three pairs of broad lateral teeth; no

median teeth; adcauline edge indented.

Median inferior nematotheca of variable length, adnate to abcauline thecal

wall to approximately the level of the intrathecal septum, then free, with tip

reaching approximately to thecal margin; with one aperture extending along

upper surface of free part; with a perisarcal thickening in abcauline wall; no

opening into hydrotheca. Lateral nematotheca sac-shaped, not reaching thecal

margin, with one wide terminal aperture. Cauline nematothecae similar to

lateral.

Gonothecae (not yet found in South Africa) borne on hydrocladial

apophyses, one to each, and forming a double row on anterior surface of stem,

vase- or cup-shaped and truncated distally.

Variation. The only record from South Africa is an epizootic colony growing on

Gymnangium gracilicaule and as is so often the case in epizootic forms the

hydrothecae and nematothecae are probably somewhat stunted. The free-

living form could be expected to have better-developed marginal thecal teeth

and a longer median inferior nematotheca, with possibly two apertures, one

terminal and one on upper surface.

In this material the stem internodes usually bear one hydrocladium, and

only rarely two. In material from elsewhere two hydrocladia to an internode is

the rule and many more have been reported.

The marginal hydrothecal teeth are known to be very variable, either sharp

and pointing towards the adcauline side, or low and bluntly rounded. In var.

balei the most abcauline tooth is reduced.

The length of the median inferior nematotheca is variable in the single

colony from South Africa. In the proximal parts of the hydrocladia the adnate

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 445

part terminates below the level of the intrathecal septum and the tip does not

reach the thecal margin. In the distal parts of the hydrocladia the adnate part

terminates above the intrathecal septum and the tip overreaches the thecal

margin.

Distribution outside South Africa. Centre of distribution in East Indies from

where it extends into the Pacific Ocean to Japan, Hawaii and the Kermadec

Islands and into the Indian Ocean to the Red Sea and the east coast of Africa.

Also from the Caribbean Sea. Type locality: Torres Strait in 16 m.

Distribution in South Africa. Natal in 73 m. 30/30 (s)

Gymnangium longirostre (Kirchenpauer, 1872)

Aglaophenia longirostris Kirchenpauer, 1872: 28, 42, pl. 1 (fig. 19), pl. 5 (fig. 20).

Halicornaria longirostris: Bale, 1884: 181, pl. 13 (fig. 7), pl. 16 (fig. 3), pl. 19 (fig. 30). Mark-

tanner-Turneretscher, 1890: 279. Ralph, 1961b: 54, fig. 7 h-i. Millard, 1961: 207.

Diagnosis. Stem unfascicled, branched or unbranched, bearing alternate or

subalternate hydrocladia, divided into internodes by oblique nodes. Internodes

without septa, bearing one or two hydrocladial apophyses and three nemato-

thecae to each apophysis, two anterior and one posterior.

Hydrocladium consisting of thecate internodes separated by slightly

oblique nodes. Internodes without septa.

Hydrotheca cup-shaped, widening to margin, without intrathecal septum.

Margin forming an angle of about 60° with internode, with seven teeth, one

median abcauline incurved and three pairs of well-formed laterals of which

the two most adcauline pairs are the longest. Hydropore surrounded by minute

denticles.

Median inferior nematotheca long, adnate to abcauline thecal wall and

continued beyond it for about the same distance; free part bent distally and its

end approximately parallel to internode; with two apertures, one terminal and

one on upper surface at beginning of free part; no opening into hydrotheca.

Lateral nematotheca sac-shaped, not reaching thecal margin, with terminal and

lateral openings which may be confluent. Cauline nematotheca similar to

lateral.

Gonothecae borne on hydrocladial apophyses, small and truncated

distally.

Remarks. This species was reported by Millard from Busk’s collection of South

African hydroids in the British Museum collected in 1899. It has not been found

since and its occurrence in South Africa needs verification. The above diagnosis

has been taken from the literature.

Distribution outside South Africa. Australia (type locality), New Zealand.

Distribution in South Africa. Algoa Bay. 33/25

446 ANNALS OF THE SOUTH AFRICAN MUSEUM

Gymnangium montagui (Billard, 1912)

Fig. 134F

Aglaophenia pennatula: Hincks, 1868: 292, fig. 33, pl. 63 (fig. 3).

Halicornaria allmanii var. Marktanner-Turneretscher, 1890: 277, pl. 6 (fig. 23).

Halicornaria montagui Billard, 1912: 473, figs 6, 8. Bedot, 1921: 345.

non Sertularia pennatula Ellis & Solander, 1786: 56, pl. 7 (figs 1-2).

?Aglaophenia pennatula: Krauss, 1837: 25.

?Plumularia pennatula: Busk, 1851: 118.

Diagnosis. Stem unfascicled, unbranched, about 140 mm in height, bearing

subalternate hydrocladia, divided into internodes by oblique nodes. Internodes

bearing two closely approximate subalternate hydrocladial apophyses and three

nematothecae to each apophysis, one inferior anterior, one posterior axillary

and one anterior axillary.

Hydrocladium consisting of thecate internodes separated by oblique nodes.

Internodes without septa.

Hydrotheca cup-shaped, with convex adcauline wall and more or less

straight abcauline wall, with an abcauline intrathecal septum reaching about

half-way across, about 0,26 mm in height and 0,21 mm in marginal diameter.

Margin facing outwards, with a distinct but low triangular lateral tooth on each

side and adcauline to it a bay of varying depth, the bay never recessed below the

lateral tooth; no median teeth.

Median inferior nematotheca long, adnate to abcauline thecal wall and

continued beyond it for about the same distance, free part curved distally,

gutter-shaped and open along entire upper edge, no opening into hydrotheca.

Lateral nematotheca sac-shaped, not reaching thecal margin, with one broad

terminal aperture. Cauline nematotheca with one terminal aperture.

Gonothecae (not yet found in South Africa) borne on stem, pear-shaped,

truncated distally, smooth (Hincks).

Variation. As in the closely related G. allmanii, the margin of the hydrotheca is

variable. The lateral tooth and the bay behind it tends to be more distinct

towards the distal end of a hydrocladium (Billard 1912).

Distribution outside South Africa. Europe, Atlantic coast of Morocco. Type

locality doubtful.

Distribution in South Africa. One certain record, that of Marktanner-

Turneretscher from the Cape of Good Hope and a doubtful record from Mossel

Bay (Krauss).

Genus Lytocarpus Allman, 1883

Syn. Lytocarpia Stechow, 1919.

Macrorhynchia Stechow, 1919.

Diagnosis. Stem bearing alternate hydrocladia and usually branched and fas-

cicled. Hydrocladia unbranched. Hydrotheca cup-shaped, usually with an

abcauline intrathecal septum and a toothed margin. Median inferior nemato-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 447

theca partly adnate to abcauline thecal wall and partly free, usually long and

reaching at least to level of thecal margin, usually with two openings to the

exterior and one into the hydrotheca.

Gonothecae borne on unbranched phylactocarps which are modified

hydrocladia and may be aggregated into a pseudocorbula.

Type species: Lytocarpus spectabilis Allman, 1883

(= Plumularia phoenicea Busk, 1852).

KEY TO SPECIES

1. Hydrotheca without abcauline marginal tooth, but with two or more pairs lateral

teCth ~ 2. ne am 8 a a ee a ea is L. phoeniceus

Hydrotheca with an abcauline marginal tooth and one pair of low lateral teeth 5 eee:

2. Segments of hydrocladium sharply demarcated on posterior surface and often

produced as a spine. Abcauline thecal tooth equal to or longer than lateral teeth.

Abcauline intrathecal septum reaching about 4} distance across hydrotheca L. filamentosus

— Segments of hydrocladium not sharply demarcated on posterior surface. Abcauline

thecal tooth shorter than lateral teeth. Abcauline intrathecal septum reaching half-

way across hydrotheca or nearly so a si ay ft a L. philippinus

Lytocarpus filamentosus (Lamarck, 1816)

Fig. 137E-G

Plumularia filamentosa Lamarck, 1816: 128.

Aglaophenia ligulata Kirchenpauer, 1872: 42, pl. 1 (figs 21-22), pl. 2 (fig. 21), pl. 5 (fig. 21).

Aglaophenia fusca Kirchenpauer, 1872: 43, pl. 1 (figs 21-22), pl. 2 (fig. 22), pl. 6 (fig. 22).

Marktanner-Turneretscher, 1890: 266, pl. 6 (fig. 17).

Aglaophenia patula Kirchenpauer, 1872: 44, pl. 1 (fig. 23), pl. 2 (fig. 23), pl. 6 (fig. 23).

Lytocarpus patulus: Marktanner-Turneretscher, 1890: 274, pl. 6 (fig. 12).

Lytocarpus filamentosus: Billard, 1907a: 371, figs 15-17. Jaderholm, 1917: 18, pl. 2 (fig. 11).

Redier, 1967: 404.

Halicornaria segmentata Warren, 1908: 328, pl. 48 (figs 33-36).

Aglaophenia plumosa: Stechow, 1925a: 514 (nec. auct.)

Diagnosis. Stem fascicled, branching irregularly, reaching a maximum height of

150 mm, bearing alternate hydrocladia from an axial tube. Branches arising

from peripheral tubes of stem, unfascicled or lightly fascicled, bearing alternate

hydrocladia. Axial tube of stem and branch with a hinge-joint separating a short

basal part bearing median nematothecae only, from a distal part bearing hydro-

cladia; basal part segmented, often indistinctly, distal part divided into regular

internodes by oblique nodes. Each internode bearing one hydrocladial apophysis

and two nematothecae, one inferior anterior and one axillary anterior. Mamelon

present on anterior surface of apophysis. The two rows of hydrocladia not in

one plane but displaced on to anterior surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by oblique nodes. Internodes sharply demarcated,

with distal end of posterior surface often produced as a spine, with two

internodal septa.

Hydrotheca cup-shaped and curved away from internode; with a thick

abcauline intrathecal septum reaching about one third of the distance across

448 ANNALS OF THE SOUTH AFRICAN MUSEUM

NW N

YN VF

; /, | )

} Sy Li, Y Lg eu,

} Q

Bigs 1372

Gymnangium ferlusi. A, hydrocladium; B, anterior view of stem showing gonothecae and

origins of hydrocladia; C, fertile stem.

Lytocarpus phoeniceus. D, hydrocladium.

Lytocarpus filamentosus. E, stem; F, hydrocladium; G, anterior view of stem showing

phylactocarps bearing gonothecae, and origins of hydrocladia.

Scale: C and E in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 449

and an adcauline intrathecal septum at a lower level reaching about half-way

across; 0,2-0,3 mm in abcauline height and 0,11—0,2 mm in marginal diameter.

Margin forming an angle of about 40° with internode; with three marginal

teeth, one pair broad triangular laterals and one median abcauline in the form

of a solid keel continuous basally with the abcauline intrathecal septum and

projecting distally as a sharp spine reaching to just above the level of the lateral

teeth.

Median inferior nematotheca adnate to abcauline thecal wall as far as

the abcauline intrathecal septum, then free; free part tapering, straight or curved,

usually overtopping median tooth; with three openings, one transversely

elongated distal, one on upper surface at base of free part and one into hydro-

theca. Lateral nematotheca tubular, overtopping thecal margin, with two

apertures, one distal and one mesial. Cauline nematothecae conical, with two

apertures, one distal and one lateral. Nematothecae on basal part of branch

broad, with two distal apertures directed sideways.

Phylactocarp replacing every third hydrocladium, displaced towards

anterior surface of branch, curved, twisted through 180° after first internode,

consisting of one normal thecate internode, one internode in which the hydro-

theca is replaced by a gonotheca, and a distal region of variable length with

indistinct segmentation bearing pairs of nematothecae only. Gonotheca lens-

shaped, more flattened on adcauline side.

Variation. Young colonies have unbranched stems which may be unfascicled.

Nodes may be indistinct or absent on the stem or on the basal parts of older

branches. Occasionally two subopposite hydrocladia arise from one branch

internode; these have between them three cauline nematothecae, one inferior

to each and one shared anterior axillary. Only the lower apophysis bears a

mamelon. On the first internode of a hydrocladium the median inferior nemato-

theca is shorter than usual and does not reach the margin of the hydrotheca.

Remarks. Stechow’s material from the Agulhas Bank, which he assigned to

Aglaophenia plumosa Bale in 1925, is none other than a young colony of

L. filamentosus. This was ascertained by examination of a slide prepared by

Stechow kindly loaned by the Munich Museum.

Distribution outside South Africa. Australia (type locality), Madagascar, Vema

Seamount (South Atlantic).

Distribution in South Africa. South West Africa to Natal, littoral to 80 m.

34/18 (1, s), 35/19 (s), 34/20 (s), 34/21 (s), 34/22 (s), 34/23 (s), 33/25 (s), 34/25

(s), 33/27 (s), 31/29 (1, s), 30/30 (1), 29/31 (s), 28/32 (s)

Lytocarpus philippinus (Kirchenpauer, 1872)

Fig. 138A—C

Aglaophenia Philippina Kirchenpauer, 1872: 29, 45, pl. 1 (fig. 26), pl. 2 (fig. 26), pl. 7 (fig. 26).

Lytocarpus philippinus: Nutting, 1900: 122, pl. 31 (figs 4-7). Vervoort, 1968: 88, fig. 41.

Macrorhynchia philippina: Gravier 19706: 253, fig. 1.

450 ANNALS OF THE SOUTH AFRICAN MUSEUM

Diagnosis. Stem fascicled, branching irregularly, reaching a maximum height

of 155 mm, bearing alternate hydrocladia from an axial tube. Branches arising

from peripheral tubes of stem, unfascicled or lightly fascicled, divided by a

hinge-joint into a short unsegmented basal part bearing median nematothecae

only, and a distal part bearing alternate hydrocladia. Axial tube of stem and

distal part of branch divided into internodes by oblique nodes, each internode

bearing one hydrocladial apophysis and two nematothecae, one inferior anterior

and one axillary anterior. Mamelon present on anterior surface of apophysis.

The two rows of hydrocladia not in one plane but displaced on to anterior

surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by transverse or slightly oblique nodes. Internodes

with two internodal septa.

Hydrotheca cup-shaped and curved away from internode; with a thick

abcauline intrathecal septum reaching about half-way across and an adcauline

intrathecal septum at a lower level overarching the hydropore; 0,15—0,2 mm in

abcauline height and 0,14-0,20 mm in marginal diameter. Margin forming an

angle of 30-40° with internode; with three marginal teeth, one pair broad

triangular laterals and one median abcauline in the form of a solid keel contin-

uous basally with the abcauline intrathecal septum and projecting distally as a

short spine which does not quite reach the level of the lateral teeth.

Median inferior nematotheca adnate to abcauline thecal wall as far as the

abcauline intrathecal septum, then free; free part more or less straight, usually

overtopping thecal margin; with three openings, one rounded distal, one on

upper surface at base of free part and one into hydrotheca. Lateral nematotheca

tubular, overtopping thecal margin, with two apertures, one distal and one

mesial. Cauline nematothecae conical, with two apertures, one distal and one

lateral. Nematothecae on basal part of branch broad, with two distal apertures

directed sideways.

Phylactocarp replacing every third hydrocladium, displaced towards

anterior surface of branch, consisting of one normal thecate internode, then one

or (usually) two internodes in which the hydrotheca is replaced by a gonotheca,

then a distal region twisted through 180° and consisting of up to four internodes

bearing nematothecae only. Gonotheca lens-shaped.

Colour: stem black or brown, hydrocladia cream.

Variation. Young colonies have unbranched and unfascicled stems.

The arrangement of branches on the stem is very irregular; usually there

are two rows, in one plane or displaced anteriorly, with variable intervals between

them, and they may be opposite, alternate or quite irregular.

On the first internode of the hydrocladium the median inferior nematotheca

is Shorter than usual and barely reaches the level of the lateral marginal teeth.

On the phylactocarp the number of nematothecae on the internodes of the

distal part varies, there are usually two, sometimes three and sometimes one.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 45]

Gravely (1927) says the species ‘stings like a nettle when touched’.

Gravier (1970b) describes the release of degenerate medusae from the

gonothecae. These are without tentacles, mouth and canals, but have a

hypostome and velum and a circle of refringent corpuscles round the margin.

Distribution. Circumglobal in tropical and subtropical waters. Type locality:

Manilla, Philippine Islands.

Distribution in South Africa. Natal and Mocgambique, littoral to 44 m. 29/31 (s),

DGS2) (ls S)) 29/325 24/351(s);, 23/35 (y's), 21/35

Lytocarpus phoeniceus (Busk, 1852)

Fig. 137D

Plumularia phoenicea Busk, 1852: 398.

Lytocarpus spectabilis Allman, 1883: 43, fig. 2, pl. 15.

Aglaophenia phoenicea: Bale, 1884: 159, pl. 15 (figs 1-5), pl. 17 (figs 1-4), pl. 19 (fig. 31).

Lytocarpus phoeniceus: Billard, 1910: 48, fig. 22. Billard, 1913: 74, figs 60-61. Millard 1968:

284.

Diagnosis. Stem fascicled, branching pinnately and in one plane, reaching a

maximum height of 39 mm, bearing alternate hydrocladia from an axial tube.

Branches arising from peripheral tubes of stem, unfascicled or lightly fascicled,

consisting of a short, unsegmented basal part bearing median nematothecae

only and a distal part bearing alternate hydrocladia, but no hinge-joint. Axial

tube of stem and distal part of branches indistinctly segmented, the segmentation

being more obvious in unfascicled parts, where each internode bears one

surface of apophysis. The two rows of hydrocladia arising from anterior

hydrocladial apophysis. Two nematothecae associated with each apophysis,

one inferior anterior and one axillary anterior. Mamelon present on anterior

surface of stem and curved outwards to lie in one plane.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by transverse or slightly oblique nodes. Internodes

with two septa.

Hydrotheca cup-shaped and curved away from internode; with an abcauline

intrathecal septum stretching over half-way across and a short adcauline

intrathecal septum at a lower level overarching the hydropore; 0,12-0,17 mm in

abcauline height and 0,13-0,16 mm in marginal diameter. Margin forming an

angle of about 30° with internode; with one or two pairs of broad and low

triangular lateral teeth and a small rounded lobe on adcauline edge, no

abcauline tooth.

Median inferior nematotheca adnate to abcauline thecal wall to approxi-

mately the level of the abcauline intrathecal septum, then free; free part bent

distally at an angle to adnate part, straight, usually overtopping thecal margin;

with three openings, one distal, one on upper surface at base of free part and one

small one into hydrotheca. Lateral nematotheca tubular, overtopping thecal

margin, with two apertures, one distal and one mesial. Cauline nematothecae

saccular, with two distal openings.

ANNALS OF THE SOUTH AFRICAN MUSEUM

452

Ql lllllie

UG.

Lytocarpus philippinus. A, hydrocladium; B, anterior view of stem showing one phylactocarp

bearing gonothecae, and origins of hydrocladia; C, stem.

Thecocarpus formosus. D, stem; E and F, hydrothecae with short and long spines; G, female

corbula.

Scale: C and D in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 453

Phylactocarps (not yet reported from South Africa) replacing every third

hydrocladium, strongly curved, consisting of one normal thecate internode,

then one internode in which the hydrotheca is replaced by a gonotheca, then a

distal region consisting of six or more segments each bearing two or three

nematothecae only. Gonotheca lens-shaped.

Variation. Although only small colonies are known from South Africa, this

species is known to form magnificent fan-shaped colonies up to 200 mm in

height and with a thick, branching stem. The branches in turn bear secondary

branches with a pinnate arrangement.

According to the literature there is much variation in the character of the

marginal thecal teeth. There may be as many as four pairs of small lateral teeth

and the adcauline rounded lobe may be produced into a tooth which is either

straight or curved over the hydrotheca. So far these variations have not been

observed in South Africa. ;

Distribution outside South Africa. Tropical Indo-Pacific, from the Pacific

Ocean to the east coast of Africa. Type locality: Torres Strait in 16 m.

Distribution in South Africa. Natal, 49-64 m. 29/31 (s)

Genus Thecocarpus Nutting, 1900

Syn. Lytocarpa Kirchenpauer, 1872.

Diagnosis. Stem branched or unbranched, bearing alternate hydrocladia. Hydro-

cladia unbranched. Hydrotheca sac-shaped to deep, usually with toothed margin

and often with a median keel-like spine outside the abcauline tooth. Median

inferior nematotheca fairly short, usually not reaching thecal margin. Gono-

thecae in corbulae formed by modified hydrocladia bearing secondary ribs.

Ribs bearing nematothecae and at least some of them in at least one sex, bearing

one hydrotheca.

Type species: Sertularia myriophyllum Linnaeus, 1758.

KEY TO SPECIES

1. Stem branched, each branch forming a spirally twisted sympodium. Hydrotheca

usually with a second point outside abcauline marginal tooth of approximately the

same length and which may be solid or hollow .. Bye Lb ee T. flexuosus

— Stem unbranched, or if branched, not as a sympodium .. “ a on ioc BD)

2. Hydrotheca with long, hollow, curved spine arising from abcauline surface outside

abcauline marginal tooth .. a at tus aa ae ju T. formosus

— Hydrotheca with no spine or second point outside abcauline marginal tooth ee 3

3. Hydrotheca sigmoidally curved, margin with seven teeth, of which four may be

bitids a: se a 1s a as ois si a fe T. brevirostris

— Hydrotheca sac-shaped, margin with five distinct teeth and sometimes two rounded

lobes .. a = ak a Ke ae ae a a T. delicatulus

454 ANNALS OF THE SOUTH AFRICAN MUSEUM

Thecocarpus brevirostris (Busk, 1852)

Fig. 139A-—C

Plumularia brevirostris Busk, 1852: 397.

Plumularia Vitiana Kirchenpauer, 1872: 34, pl. 1 (fig. 9), pl. 3 (fig. 9).

Aglaophenia vitiana: Billard, 1907a: 388, figs 22-23.

Thecocarpus brevirostris: Billard, 1910: 51, fig. 24. Billard, 1913: 89, fig. 75. Stechow, 1919b:

137, figs A?, B®. Jarvis, 1922: 350, pl. 26 (fig. 24). Millard, 1968: 284, fig. 6B.

Diagnosis. Stem unfascicled and unbranched in young colonies, fascicled and

branched in old ones, reaching a maximum height of 90 mm. Branching roughly

alternate and strictly in one plane; branches arising from superficial tubes of

stem, themselves often fascicled and rebranched. Stem and branches bearing

alternate hydrocladia, divided into internodes by transverse nodes in the younger

parts only. Two nematothecae to each hydrocladial apophysis, one inferior

anterior and one axillary anterior. Mamelon present on anterior surface of

apophysis. The two rows of hydrocladia arising from anterior surface of stem

and directed outwards to lie in the same plane as the branches.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by slightly oblique nodes. Internodes with a variable

number of septa.

Hydrotheca deep, with that part of abcauline wall above the level of the

median nematotheca at least slightly concave and thickened, with a short

adcauline intrathecal septum about one-fifth of height from base, 0,2—0,3 mm

in abcauline height and 0,10-0,16 mm in marginal diameter. Margin forming

an angle of 50-60° with internode; with seven marginal teeth, one median

abcauline and three pairs laterals, of which the two most abcauline may be

bifid.

Median inferior nematotheca adnate to thecal wall for about half height

of latter, then free and bent away from it, usually not reaching to thecal margin,

with three apertures, one terminal, one on upper surface at base of free part

(these two often confluent) and one into hydrotheca. Lateral nematotheca

tubular and bent backwards, reaching thecal margin, with two apertures, one

terminal and one mesial (these two sometimes confluent).

Corbula with a pedicel of two hydrotheca-bearing segments, bearing 6-8

pairs of ribs and terminating in one or two hydrotheca-bearing segments. Each

rib bearing proximally a perisarcal crest supporting one hydrotheca and two

lateral nematothecae, and continued as a broad blade with nematothecae on

the outer edge and fused to the rib behind by the inner edge. Outer edge of rib

often with a leaf-like outgrowth bearing one or more nematothecae.

Colour: rich brown.

Variation. Several authors have noted a tendency to reverse the faces of the

stem, so that in the lower part the hydrocladia face one Way and in the upper

part the opposite way. This has not been observed in South Africa.

Considerable variation occurs in the hydrocladial internodes. Internodal

septa may be poorly developed and limited to one opposite the intrathecal sep-

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 455

tum, or there may be two fairly distinct ones, the second situated behind the

centre of the hydrotheca. The intrathecal septum may be very short or may

extend halfway across the hydrotheca. The depth of the hydrotheca varies and

this influences the curvature of the abcauline wall abovet he level of the median

nematotheca, which may be short, strongly concave and distinctly thickened,

or long, weakly concave and only slightly thickened. Variation also occurs along

the length of the hydrocladium, the first hydrotheca commonly being shorter

and with a more distinctly curved abcauline wall than the last one. The first

and second pairs of marginal teeth may be simple and triangular, or subdivided.

The length of the median inferior nematotheca is also variable but it does not

reach beyond the level of the thecal margin.

It is to be noted that in the only two corbulae seen in South Africa, there

are two hydrothecate internodes on the pedicel, whereas only one is reported

from other areas.

Distribution outside South Africa. South Pacific islands, northern Australia,

tropical Indian Ocean from the East Indies to Africa. Type locality: off Cumber-

land Island, Queensland, in 49 m.

Distribution in South Africa. Natal and Mocambique, in 2-70 m. 29/31 (s), 29/32

(s), 28/32 (s), 25/33 (s), 24/35 (s)

Thecocarpus delicatulus (Busk, 1852)

Fig. 139D-E

Plumularia delicatula Busk, 1852: 396.

ee delicatula: Bale, 1884: 167, pl. 14 (fig. 4), pl. 17 (fig. 11). Billard, 1913: 106,

ee delicatulus: Millard & Bouillon, 1973: 94, fig. 11J—K.

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 30 mm,

bearing alternate hydrocladia, with one or two hinge-joints separating a short

basal part from a distal hydrocladia-bearing part. Distal part divided into

internodes by slightly oblique nodes, each internode bearing one hydrocladial

apophysis and three nematothecae, one inferior anterior, one axillary anterior

and one axillary posterior. Mamelon present on anterior surface of apophysis.

The two rows of hydrocladia arising from the anterior surface of the stem and

curving backwards.

Hydrocladium bearing close-set hydrothecae on anterior surface, consisting

of thecate internodes separated by transverse nodes; each internode usually

with two internodal septa, one opposite the intrathecal septum and one opposite

the base of the lateral nematotheca.

Hydrotheca sac-shaped, with a complete intrathecal septum at about

é of height, 0,18-0,2 mm in abcauline height and 0,13-0,16 mm in marginal

diameter. Margin forming an angle of 55—60° with internode; with five distinct

marginal teeth, one median inturned abcauline and two triangular laterals on

each side of it, adcauline half of margin straight or sinuated.

alo)

ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 139.

Scale: A and D in cm, the rest in mm/10.

S iH)

KCK

S Wf I) CU ia

SS Ue Gh (/}; YW; Uff LR KC |

456

Thecocarpus brevirostris. A, stems; B, corbula (openings into interior shaded); C, distal and

proximal regions of hydrocladium.

Thecocarpus delicatulus. D, stem; E, hydrocladium.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 457

Median inferior nematotheca adnate to abcauline thecal wall to just below

origin of marginal teeth, then free; reaching approximately to tips of marginal

teeth; with an aperture extending all the way along upper surface of free part

and another into hydrotheca. Lateral-nematotheca tubular, curved, reaching

just beyond level of thecal margin, with one distal aperture extending also along

mesial surface.

Corbula (not reported from South Africa) replacing hydrocladium, con-

sisting of a pedicel of one thecate segment followed by about ten segments

bearing alternate ribs. Corbula open and ribs quite free. Each rib with one

hydrotheca near base subtended by a pair of lateral nematothecae and followed

by a double series of alternate nematothecae.

Variation. In the younger (distal) parts of the hydrocladia the more proximal of

the two internodal septa tends to disappear. The adcauline half of the thecal

margin may be quite straight or a distinct rounded lobe may be present.

Distribution outside South Africa. Tropical Indo-Pacific, from the east coast of

Africa to Queensland. Type locality: Torres Strait in 16 m.

Distribution in South Africa. Santa Carolina in Mocambique, only. 21/35

Thecocarpus flexuosus (Lamouroux, 1816)

Figs. 140-141

Aglaophenia flexuosa Lamouroux, 1816: 167.

Thecocarpus filexuosus: Millard, 1962: 312, fig. 12.

Diagnosis. Stem fascicled and branching irregularly, generally thick and woody

at base. Branches unfascicled or lightly fascicled, in the form of a scorpioid

sympodium, the whole twisted in a spiral manner and with each successive

podium arising from the anterior surface of the one before and facing towards it.

Each podium typically divisible into a basal part divided into internodes

bearing one large median nematotheca each, and a distal part, continued to end

of branch and divided into internodes bearing one hydrocladium and three

nematothecae each. Nodes transverse or slightly oblique. Nematothecae of

hydrocladium-bearing segment including one axillary anterior, one axillary

posterior and one inferior anterior. A mamelon present on anterior surface of

hydrocladial apophysis. Hydrocladia alternate, the two rows not in one plane

but shifted onto anterior surface.

Hydrocladium bearing hydrothecae on anterior surface, consisting of

thecate internodes separated by slightly oblique nodes. Internodes typically

with two septa.

Hydrotheca sac-shaped, expanding to margin, with an adcauline intrathecal

septum near base, 0,2—0,4 mm in abcauline height and 0,14-0,2 mm in marginal

diameter. Margin forming an angle of 50-70° with internode; with nine marginal

teeth, one median abcauline and four pairs laterals, some of which may be

458 ANNALS OF THE SOUTH AFRICAN MUSEUM

bifid; median abcauline tooth sometimes double with an internal and an

external point.

Median inferior nematotheca short, adnate to abcauline thecal wall to

approximately level of intrathecal septum, then free; never reaching level of

thecal margin; with one aperture extending along upper surface of free part; no

Opening into hydrotheca. Lateral nematotheca tubular, reaching to thecal

margin, with one aperture. Cauline nematothecae sac-shaped, with three to six

apertures.

Corbula with a pedicel of one to seven hydrotheca-bearing segments

followed by segments bearing alternate paired ribs. Each rib bearing a series of

nematothecae along outer edge, a hydrotheca near the base and a crested process

of variable length proximal to the hydrotheca. Corbula closed, with inner edge

of each rib fused to the rib behind. Proximal side of first rib with a rounded

projection facing towards pedicel.

KEY TO SUBSPECIES

[Subspecies not represented in South Africa are bracketed]

1. Sympodial branches with umbel-like appearance: first podium long, subsequent ones

short and forming a close spiral .. ne .. TT. f. umbellatus

— Sympodial branches not umbel-like: all podia of approximately the same length and

forming a loose or tight, but regular, spiral - a i Be = 0 ie

2. Abcauline thecal tooth simple, with no outer point a aS 3. ff. fi plamifents

— Abcauline thecal tooth double, with an inner and an outer point

3. Outer point of abcauline thecal tooth normally solid... - oe T. f. solidus

— Outer point of abcauline thecal tooth normally hollow ae ae BE shot at

4. Median nematotheca often bifurcated, lateral nematotheca with two openings

[T. f. perarmatus|

— Median nematotheca not bifurcated, lateral nematotheca with one opening 7. f. flexuosus

Thecocarpus flexuosus flexuosus (Lamouroux, 1816)

Fig. 140A—C

Aglaophenia flexuosa Lamouroux, 1816: 167.

Thecocarpus giardi: Billard, 1907a: 381, fig. 21, pl. 25 (fig. 9), pl. 26 (figs 11-16). Vervoort,

19466: 335. Millard, 1957: 240. Millard, 1958: 221, fig. 16A.

Thecocarpus flexuosus: Billard, 1909: 330. Redier, 1967: 406.

?Aglaophenia bifida Stechow, 1923b: 117. Stechow, 1925a: 515, fig. 53.

Thecocarpus flexuosus flexuosus: Millard, 1962: 315, fig. 12A, J-L.

Diagnosis. Colony reaching 238 mm. Sympodium geniculate and twisted in a

spiral which may be tight or loose. Podia of approximately equal length, with

no regular hinge-joints. Hydrocladia usually short and about 6 mm in length.

Hydrothecal margin with the two most abcauline lateral teeth typically

bifid; median abcauline tooth double, with the outer point hollow and longer

than the inner.

Corbula reaching 7 mm and bearing up to 13 pairs ribs. Crested processes

of ribs sometimes produced and bearing nematothecae.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

WX wT

COU WQa]iVwwx,”

| I QY WT || LE

My, Xi

=< Vi

a 4

fi (- EE

" ZINE i

= GZ

RSS os = -

—

—= =

\ =

— SJ

| SS

Fig. 140.

Thecocarpus flexuosus flexuosus. A, part of stem including one spirally twisted sympodial

branch; B, hydrothecae; C, corbula.

Thecocarpus flexuosus solidus. D, hydrothecae.

Scale: A in cm, the rest in mm/10.

460 ANNALS OF THE SOUTH AFRICAN MUSEUM

Distribution outside South Africa. Madagascar. Type locality: East Indies.

Distribution in South Africa. False Bay to Mocgambique in 5 to 100 m. 34/18 (s),

235/20 (d), 34/21 (s), 34/23 (s), 33/28 (s), 30/30 (s), 29/31 (Ss), 28/32 (d), 24/34 (s)

Thecocarpus flexuosus plumiferus (Kirchenpauer, 1872)

Fig. 141B, D

Aglaophenia plumifera Kirchenpauer, 1872: 31, pl. 1 (fig. 6), pl. 3 (fig. 6). Stechow, 1923c:

iff eee pee plumiferus: Millard, 1962: 313, fig. 12C—D.

Diagnosis. Colony reaching 460 mm. Sympodium of branch not obviously

geniculate, twisted in a spiral which may be tight or loose. Podia of approxi-

mately equal length, usually with hinge-joints separating basal and distal parts

and situated distal to origin of next podium. Hydrocladia short, 3-6 mm in

length.

Marginal teeth of hydrotheca not bifid; median abcauline tooth simple,

with no outer point, though abcauline wall somewhat thickened near margin.

Corbula sometimes very long, reaching 20 mm and bearing up to 39 pairs

ribs.

Variation. Occasional hydrothecae show the beginnings of an outer point on the

abcauline thecal tooth, thus tending towards subsp. solidus, but this secondary

point never equals the abcauline tooth in length.

Distribution. Endemic to South Africa. Type locality: Algoa Bay.

Distribution in South Africa. Agulhas Bank from off Still Bay to off East London

in 50 to 104 m. 34/21 (s), 33/35, 33/26 (d), 33/27 (s), 32/28 (s)

Thecocarpus flexuosus solidus (Millard, 1958)

Fig. 140D

Thecocarpus giardi var. solidus Millard 1958: 222, fig 16B-C.

Thecocarpus flexuosus solidus: Millard, 1962: 316, fig. 12E-H.

Diagnosis. Colony reaching 550 mm, very similar in appearance to subsp.

flexuosus. Sympodium of branch more or less geniculate, twisted in a spiral

which may be tight or loose. Podia of approximately equal length, usually with

one or two hinge-joints separating basal and distal parts and situated proximal

or distal to origin of next podium. Hydrocladium short, about 6 mm in length.

Marginal teeth of hydrotheca not bifid; median abcauline tooth double,

with outer point forming a solid spine and longer than the inner.

Corbula reaching 5 mm in length and bearing up to 16 pairs ribs.

Variation. Rarely the outer point of an abcauline thecal tooth may be hollow,

resembling subsp. flexuosus, and rarely the outer point may be poorly developed,

resembling subsp. plumiferus.

Examples have been seen of a double corbula, in which the pedicel bifurcates

in the fifth segment, and also of branching hydrocladia.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 461

Distribution. Endemic to South Africa. Type locality: off Natal, 28°28’S/

32°25, E, 2) i.

Distribution in South Africa. Agulhas Bank off Still Bay to Mocambique in 18

to 110 m. 35/21 (d), 33/26 (s), 33/27 (s), 33/28 (s), 32/28 (s), 30/30 (s), 30/31 (s),

29/31 (s), 29/32 (s), 28/32 (s), 25/33 (s), 24/35 (d)

Thecocarpus flexuosus umbellatus Millard, 1962

Fig. 141A, C

Thecocarpus flexuosus: Millard, 1961: 208 (specimen 1899.7.1.6093 only, others too fragmen-

tary to establish subspecies).

Thecocarpus flexuosus umbellatus Millard, 1962: 316, fig. 12B, M.

Diagnosis. Colony reaching 138 mm. Branches like an umbel in appearance,

sympodium formed from one long podium followed by several very short ones

(usually five in all), the whole spirally twisted. Two hinge-joints present in first

podium, separating basal and distal parts. ‘Umbels’ breaking easily at hinge-

joints and commonly occurring separately in dredges. Podia other than the

first with no hinge-joints and no basal part. Hydrocladia long, reaching 15 mm.

Marginal teeth of hydrotheca not bifid; median abcauline tooth double,

with outer point hollow and longer than inner.

Corbula reaching 12 mm and bearing up to 20 pairs ribs. Terminal parts of

ribs and their crested processes sometimes produced to give a spidery

appearance.

Variation. Although the first podium is always the longest, subsequent ones are

occasionally longer than normal, so tending towards subspecies flexuosus.

Distribution. Endemic to South Africa. Type locality: Agulhas Bank, 32°15,2’S/

28°57,7'E, 49,5 m.

Distribution in South Africa. Agulhas Bank, from off Still Bay to off East London

in 18 to 120 m. 34/21 (s), 33/25 (s), 34/25 (s, d), 33/26 (d), 34/26 (d), 33/27 (s),

32/28 (s)

Thecocarpus formosus (Busk, 1851)

Fig. 138D-G

Plumularia formosa Busk, 1851: 118.

Aglaophenia formosa: Marktanner-Turneretscher, 1890: 264, pl. 6 (fig. 11).

Thecocarpus formosus: Billard, 1907a: 378, figs 19-20. Vervoort, 19465: 332, fig. 7. Millard,

1958: 221. Rees & Thursfield, 1965: 184.

Aglaophenia parasitica Warren, 1908: 332, fig. 17, pl. 48 (figs 28-32).

Diagnosis. Stem unfascicled, unbranched, reaching a maximum height of 240

mm, with one to three hinge-joints separating a short basal part from a distal

part bearing alternate hydrocladia. Distal part divided into short, broad inter-

nodes by transverse or oblique nodes sloping in alternate directions. Each inter-

node bearing one hydrocladial apophysis and three nematothecae, one inferior

anterior, one axillary anterior and one axillary posterior. Mamelon present on

462 ANNALS OF THE SOUTH AFRICAN MUSEUM

\\ \\ \\V\ 44) YD

| | i| / SF> i

| | y yj Z "

EA | / N

\ |

— \ —<—==_ SAVY i

VFO tw, Pe

i SZ Z :

NS (WA

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A.D

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O yy

co p

7 yz

Fig. 141.

Thecocarpus flexuosus umbellatus. A, a sympodial branch; C, hydrothecae.

Thecocarpus flexuosus plumiferus. B, hydrothecae; D, a sympodial branch bearing corbulae.

Scale: A and D in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 463

anterior surface of apophysis. The two rows of hydrocladia not in one plane,

but displaced onto the anterior surface.

Hydrocladium bearing close-set hydrothecae on anterior surface, consisting

of thecate internodes separated by transverse or slightly oblique nodes. Inter-

nodes with or without an internodal septum across central region, last internode

with an extra median nematotheca and terminating in a blunt spine.

Hydrotheca sac-shaped, with an adcauline intrathecal septum, 0,2-0,3 mm

in abcauline height and 0,13-0,19 mm in marginal diameter. Margin forming

an angle of about 60° with internode; with seven marginal teeth, one median

inturned abcauline and three pairs double laterals, each with an internally and

an externally directed point, the external point of the most adcauline tooth

the largest; with a long, hollow spine arising from the abcauline surface below

the median abcauline tooth and curving distally.

Median inferior nematotheca adnate to abcauline thecal wall as far as the

median spine, then free; not quite reaching thecal margin; with an aperture

extending all the way along upper surface of free part and sometimes a second

opening into hydrotheca. Lateral nematotheca tubular, reaching approximately

to level of thecal margin, with one distal aperture extending also along mesial

surface. Cauline nematothecae gutter-shaped.

Corbula with a pedicel of two to five hydrotheca-bearing segments followed

by segments bearing alternate paired ribs. Each rib bearing a series of long

tubular nematothecae along outer edge, and with inner edge fused to the rib

behind. Each rib with a free lateral branch close to proximal end bearing nema-

tothecae on both edges. A hydrotheca seated in axil of lateral branch. Corbula

reaching 3-11 mm in length. Female corbula with ribs very firmly attached;

each rib with proximal branch well developed and sometimes equal to it in

length, often with one or two extra lateral branches distal to hydrotheca.

Male corbula usually longer and thinner than female and with distal parts of

ribs only partly attached; each rib with a proximal lateral branch only, which is

poorly developed and bears at most two or three pairs nematothecae.

Colour: reddish brown.

Variation. The hydrorhiza of this species has the ability to produce suckers

which act as holdfasts. Since the suckers can penetrate into pebbles, barnacle-

Shells and coralline algae (a common host), they must produce some calcium-

dissolving substance. It has been shown by Warren (1908) that they can also

penetrate into the cells of the host algae where they possibly obtain nourishment.

The size of the hydrotheca varies along the length of a hydrocladium,

tending to be smaller near the proximal end and with a shorter median inferior

nematotheca. The change in length in the median spine is most marked; its

length being approximately 0,03 mm at the proximal end, increasing gradually

to as much as 0,3 mm at about five internodes from the distal end, then becoming

shorter again.

Distribution outside South Africa. Ceylon, Torres Strait (Australia) and

464 ANNALS OF THE SOUTH AFRICAN MUSEUM

Mediterranean, with doubtful records from Labrador and New Zealand.

Distribution in South Africa. Common‘all round the south and east coasts from

off Still Bay to Richard’s Bay, littoral to 90 m. One record from South West

Africa. Type locality: Algoa Bay. 34/21 (s), 34/22 (s), 34/23 (s), 33/25 (s), 34/25

(s), 33/26 (s), 33/27 (, s), 32/28 (1, s), 32/29 (s), 31/29 C, s), 31/30 Cd), 30/30 (s);

29/31 (1, s), 28/32 (s)

SUBORDER: LIMNOMEDUSAE

Diagnosis. Hydranth usually small, sessile and solitary, but with powers of

asexual reproduction; with no definite hydrotheca or gonotheca; with or without

a few tentacles; producing medusae. Medusa with gonads either on stomach or

on radial canals; with hollow marginal tentacles usually without marginal

bulbs; with or without endodermal statocysts.

KEY TO FAMILIES

[Families not treated in this monograph are bracketed]

1. Medusa with gonads on radial canals only; with statocysts but without ocelli [OLINDIIDAE]

Medusa with gonads on stomach, but often extending along radial canals as well... 2

2. Medusa generally with branched radial canals; without statocysts and without

ocelli. Hydranth with not more than 2 tentacles .. Be PROBOSCIDACTYLIDAE Pp. 467

Medusa with unbranched radial canals... oe S45 a eS

3. Medusa without statocysts but with ocelli. Hydranth with more than 2 tentacles

MOERISIIDAE p. 464

— Medusa with statocysts but without ocelli. Hydranth without tentacles [LIMNOCNIDIDAE]

Family Moerisiidae

Diagnosis. Hydranths small and athecate, normally solitary, with more than

two capitate or moniliform tentacles, with conical hypostome. Perisarc poorly

developed, never reaching to tentacular region. Asexual reproduction possible

by budding, transverse fission or stolonization.. Producing medusa-buds on

hydranth body.

Medusa with four unbranched radial canals, at least four hollow marginal

tentacles, usually no statocysts, abaxial ocelli on marginal bulbs, quadrangular

stomach. Gonads on stomach wall and on radial lobes of stomach extending

outwards along radial canals.

Nematocysts of three kinds, always including stenoteles and desmonemes.

Mostly brack-water forms.

Introduction. The family Moerisiidae contains a number of relatively rare forms

known from brackish waters in various parts of the world. One or two forms

can also exist in the sea. There are in total only five genera and nine species.

The species are known best by their medusae, which are of moderate size. The

hydranth generation is relatively inconspicuous and is known in six species. It

lives attached to water-weeds, grass, sand-grains, etc., and though essentially

solitary, possesses the power of asexual reproduction.

The hydranth is athecate; the tentacles are scattered on the distal part of the

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 465

body or arranged in one or two rough whorls and are moniliform or capitate.

Medusa-buds are borne on the hydranth body, either amongst or below the

tentacles. A poorly developed perisarc occurs, which surrounds the stolons when

present (see below), may continue for a short distance over the hydranth body

and in some species forms thickened PEDAL Discs for attachment.

Asexual reproduction may occur in several ways.

(i) By transverse fission (‘decapitation’), described for Moerisia lyonsi.

(ii) By production of lateral buds, usually immediately below the tentacles. The

buds separate off, produce tentacles and develop into new hydranths. Occa-

sionally a bud may fail to separate and develops a hydranth in situ.

(iii) By stolonization. The base of the hydranth produces slender, branching

stolons which give rise to new hydranths which sooner or later separate off

from the parent body.

(iv) In some species the basal discs, which contain an extension of the body wall,

act as resting stages (PODOCYSTS) and can survive the death of the hydranth

to regenerate later. They can also divide, each daughter podocyst producing a

hydranth.

Unlike most hydroids both hydranth and medusa possess hollow tentacles,

their cavities communicating directly with the coelenteron.

The medusa is peculiar in the cruciform shape of its stomach, of which four

lobes spread outwards along the radial canals. The gonads develop on the

stomach wall and on its radial lobes, sometimes almost reaching the margin of

the bell. The reddish ocelli on the marginal bulbs are a prominent feature.

Kramp, in various papers, includes the Moerisiidae, together with the

Olindiidae, Limnocnididae and Proboscidactylidae, in the order Limnomedusae,

mainly on the basis of the hollow tentacles and the quadrate nature of the

stomach in the medusa. The Olindiidae and Limnocnididae have internal

statocysts but there is some doubt as to their presence in the Moerisiidae. Kramp

claims to have found microscopic statocysts in Ostroumovia, a claim which,

however, is rejected by Valkanov (1954).

Rees (1958) on the other hand, places the Moerisiidae among the capitate

Athecata, where he creates a superfamily, Moerisioidea, for their reception.

He claims that they have many features in common with the lower Cory-

morphines, including the nematocyst types. All Moerisiidae have three types

of nematocysts: stenoteles, desmonemes and a third type which is variable:

isorhizas in Ostroumovia inkermanica, atrichous isorhizas in Moerisia lyonsi,

basitrichous isorhizas in Ostromouvia horii, anisorhizas in Ostroumovia gemmata

and microbasic euryteles in Odessia maeotica.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Hydranth tentacles capitate and with adaxial batteries of nematocysts. Fixation by

pedal disc. Medusa tentacles with irregular transverse batteries of nematocysts

[Odessia]

— Hydranth and medusa tentacles moniliform, with complete rings of nematocysts along

the whole length aa ies :

466 ANNALS OF THE SOUTH AFRICAN MUSEUM

2. Fixation of hydranth by pedal discs. Medusa tentacles with basal part adnate to

exumbrella.. i: oh ae ie “ss sh bye OSTROUMOVIA, p. 466

— Hydranth without pedal discs, loosely attached by thin perisarcal covering of hydro-

rhiza. Medusa tentacles with globular bulbs, not clasping over exumbrella [MOERISIA ]

Genus Ostroumovia HadZi, 1928

Diagnosis. Hydranth with moniliform tentacles armed with rings of nematocysts

along whole length; tentacles irregularly arranged or in one more or less distinct

whorl. Fixation by one or more perisarcal pedal discs. Asexual reproduction by

podocysts, by budding from hydranth body, or by stolonization. Perisarc

continued as a thin, gelatinous layer over stolons and to a varying extent over

basal part of hydranth. Medusa-buds borne on body of hydranth amongst the

tentacles.

Adult medusa without peduncle, with cruciform mouth without distinct

lips, smooth gonads. Tentacles armed with annular rings of nematocysts

throughout length, with basal part adnate to exumbrella.

Type species: Moerisia inkermanica Paltschikowa-Ostroumowa, 1925.

One species from South Africa.

Ostroumovyia inkermanica (Paltschikowa-Ostroumowa, 1925)

Fig. 142A-G

Moerisia inkermanica Paltschikowa-Ostroumowa, 1925: 273, figs 1-3.

Ostroumovia inkermanica: Valkanov, 1938: 315 (German summary), various figs. Valkanov,

1950: 187, figs 1-3. Valkanov, 1954: 45 (German summary), various figs. Kramp, 1961:

216. Rees & Thursfield, 1965: 38. Kramp, 1968: 103, fig. 280. Millard, 1970: 275, fig. 1.

Diagnosis. Hydranth attached to substratum by one or more perisarcal pedal

discs, slender at base and widening to tentacular region, reaching about 3 mm

in height, with 4-12 tentacles in one whorl or in two roughly alternating whorls.

Asexual reproduction possible by lateral buds arising from the hydranth just

below the tentacles or by stolonization from the base. A delicate, gelatinous

perisarcal sheath with adhering silt covering stolons and basal part of hydranth

body.

Newly liberated medusa with four tentacles. Adult medusa hemispherical,

reaching 8 mm in diameter and 6 mm in height, with very thick jelly, very small

stomach, 32 marginal tentacles. Gonads extending along radial lobes of stomach

nearly to bell margin, with distal parts sac-like, pendent (from Kramp).

Nematocysts of three types:

(i) Stenoteles, 9,0 x 6,3 — 13,1 x 10,8 uz.

(ii) Desmonemes, 5,9 < 2,7 — 8,1 xX 4,1 pu.

(iii) A third type, probably isorhizas, present only on the hypostome of the

hydranth, with elongated capsules, 8,1 x 2,7 — 9,9 x 2,7 nu.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 467

Variation. Variation in appearance of the polyp generation occurs as a result

of asexual reproduction. The hydranth may be solitary with a single pedal disc

at the base, or stolonization at or near the base may result in a branching hydro-

rhiza with four or more pedal discs. Some of the stolons may taper off into very

fine filaments. In at least one case a new hydranth has remained attached to the

same hydrorhiza as the parent. Lateral buds occur on the hydranth body. These

are said to separate from the parent and give rise to new hydranths though

this has not been observed in this material. The pedal discs (podocysts) have the

power to divide and to regenerate after the death of the hydranth. Again this

has not been observed in South Africa.

The development of the perisarcal sheath varies among individuals and

may be hardly visible on the body of the hydranth or may reach about half-way

up its length.

Half-grown medusae (1,7 < 1,7 mm) have been found together with

the hydranths in Kosi Bay, and mature medusae (4,4 x 3,4 mm) with 16-28

tentacles in Lake St. Lucia. The known salinity range in South Africa to date is

3-10,8°/o.

Remarks. Rees & Thursfield (1965) have included Annulella gemmata Ritchie,

1915, from India and eastern Spain, as a synonym of O. inkermanica. However,

there appears to be a difference in nematocysts; Ritchie reports anisorhizas in

gemmata and Valkanov ‘glutinants’, or isorhizas, in inkermanica. It was not

possible to classify exactly the third nematocyst type in the present material.

Calder & Burrell (1969) suggest that moerisiid hydroids are distributed by

shipping, but it is hardly possible that O. inkermanica could have been intro-

duced in this way into South African lakes which are not navigable by ocean-

going vessels.

Distribution outside South Africa. Black Sea (type locality), India, France,

Netherlands.

Distribution in South Africa. Brack-water lakes: Nhlange Lake (Kosi Bay),

Lake St. Lucia and Lagoa Poelela on the east coast. Hydranths in 2-16 m,

medusae in plankton. 27/32 (s)

Family Proboscidactylidae

Diagnosis. Small athecate hydroids forming stolonial colonies commensal on

the tubes of sabellid polychaets. Perisarc totally absent. Hydranths of two types:

gastrozooids and gonozooids. Gastrozooids with two filiform tentacles and a

prominent hypostome bearing a pad of large nematocysts. Gonozooids without

mouth or tentacles, bearing gonophores which develop into free medusae.

Medusa with 4-6 or more radial canals which are generally branched,

usually with tentacles, without statocysts or ocelli, stomach with 4-6 or more

lobes extending along the proximal parts of the radial canals. Gonads on stomach

wall.

468 ANNALS OF THE SOUTH AFRICAN MUSEUM

~-medusa

bud

lateral

bud

Fig. 142.

Ostroumovia inkermanica. A—C, medusae, mature (B) and young stages (A and C):

D-G, hydranths.

Proboscidactyla sp. H, gastrozooid; J, sterile gonozooid; K, fertile gonozooid with medusa-

buds; L, older medusa-bud.

Scale: A-C in mm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 469

Nematocysts of three kinds: macrobasic euryteles, microbasic euryteles

and desmonemes.

Introduction. This family includes only two genera, Proboscidactyla and Pochella,

of which the polyp generation is known only in the former. The diagnosis is

thus based on this genus and may require modification to include Pochella

when its life-history has been traced.

The hydranths of Proboscidactyla are, in those species where they are

known, very similar to one another and cannot with any certainty be dis-

tinguished without knowledge of the medusa. Radiation has occurred in the

medusa phase and any keys must be based on medusa characters. In this genus

the medusa is distinguished by special sacs or CNIDOPHORES on the umbrella

margin between the tentacles, containing about five large nematocysts. These

are easily visible in medusa-buds still attached to the hydranth.

The life-history has been worked out for five species:

P. circumsabella Hand, 1954, by Hand;

P. flavicirrata Brandt, 1835, by Uchida & Okuda (1941) and by Hand (1954);

P. occidentalis (Fewkes, 1889), by Hand (1954);

P. ornata (McCrady, 1857), by Brinckmann & Vannucci (1965) and by Calder

(19706);

P. stellata (Forbes, 1846) by Hincks (1872) and by Browne (1896). The hydranth

of this species was originally described as Lar sabellarum by Gosse (1857)—

the posturing polyp of the British coasts.

In all of these the two-tentacled gastrozooids are arranged in a rank around

the rim of the tube of the polychaet host with their tentacles towards the cavity

and the asymmetrically placed pad of nematocysts on the hypostome away from

it. In life they are very active and perform bowing and waving movements, they

have also been seen to stroke the crown of the polychaet with their tentacles

as though salvaging food particles. When the worms spawn the eggs are

consumed in quantities by the hydranths.

Gonozooids are situated below the gastrozooids and often arise from their

bases by small ‘tails’. They may form a distinct ring or be scattered for some

distance down the tube. The lowest gonozooids are usually smaller and sterile.

The upper ones produce up to 12 medusa-buds at about 2 the height of the body.

Experimental work (Strickland 1971) has shown that the hydroids cannot

survive without their host polychaets and nor can the planulae develop. They

are thus true obligatory commensals.

In at least some species (e.g. P. ornata) the medusa can reproduce asexually

by budding either medusae or polyps from stolons which arise from the stomach

or radial canals. The medusae do not occur in mid-ocean but frequent coastal

areas and bays, habitats where the host polychaets commonly occur. In one

species, P. abyssicola (hydranth unknown) the medusa has no marginal tentacles.

Nematocysts are very similar from species to species, differing only in small

details of size and shape. In all, the same three types occur, macrobasic eury-

470 ANNALS OF THE SOUTH AFRICAN MUSEUM

teles, microbasic euryteles and desmonemes, though the microbasic euryteles

are absent from the medusae. The hydranth tentacles are remarkably poor in

nematocysts, possessing only microbasic euryteles, but all three types are pre-

sent in the nematocyst pads on the hypostome of the gastrozooid and on the

gonozooid. The largest type, the macrobasic eurytele, is very striking and

abundant.

KEY TO GENERA

[Genera not represented in South Africa are bracketed]

1. Medusa without cnidophores. Gonads on interradial walls of stomach only [Pochella]

— Medusa with cnidophores between the tentacles. Gonads extending on to radial

lobes of stomach uss a: A ie ay: ie .. Proboscidactyla p. 470

Genus Proboscidactyla Brandt, 1835

Fig. 142H-L

Syn. Lar Gosse, 1857.

Willia Forbes, 1846.

Diagnosis. Hydranth as for family.

Adult medusa with 4-6 or more branched radial canals, usually with

many marginal tentacles corresponding in number to the radial canals, rarely

without; usually without an open circular canal; with cnidophores on the

exumbrella margin between the tentacles. Gonads surrounding stomach

and extending onto its radial lobes.

Type species: Proboscidactyla flavicirrata Brandt, 1835.

Remarks. Hydranths of Proboscidactyla have been found at Inhaca, Mocam-

bique, commensal on tubes of the polychaet Laonome (Millard & Bouillon

1974), but since the medusae have not been reared it is not possible to identify

the species.

Medusae of P. ornata (McCrady, 1857), a circumglobal species, have been

found at Mombasa on the tropical east coast of Africa (Kramp 1965) and of

P. mutabilis (Browne, 1902) from Saldanha Bay on the west coast of the Cape

(University of Cape Town unpublished records, W. J. Rees det.).

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 47]

LIST OF SPECIES AND AUTHORITIES FOR PREVIOUS SOUTH

AFRICAN RECORDS

* new species,

+ new record from South Africa

ATHECATA

Family Corymorphidae

Branchiocerianthus imperator. Vervoort 19666

Corymorpha sp. Millard 1959a

Family Tubulariidae

Ectopleura bethae. Millard & Bouillon 1974

As Tubularia betheris. Warren 1908

+Hybocodon unicus

Tubularia crocea. Broch 1914. (Doubtful species)

Tubularia larynx. Stechow 1925a. Millard 19595

Tubularia warreni. Ewer 1953. Millard 1959a, 19596, 1966a

?As Tubularia sertularellae. Stechow 1923b

Zyzzyzus solitarius. Millard & Bouillon 1974

As Tubularia solitaria. Warren 19066. Millard 1957, 1966a

Family Halocordylidae

Halocordyle disticha. Millard & Bouillon 1974

As Halocordyle cooperi. Warren 1906a, 19076

As Pennaria australis var. cooperi. Warren 1908

As Halocordyle disticha var. australis. Vervoort 19466

As Pennaria disticha var. australis. Millard 1959a

Family Myriothelidae

Monocoryne minor. Millard 1966a

Mpyriothela capensis. Manton 1940. Millard 1957, 1966a

Mpriothela tentaculata. Millard 1966a

Family Corynidae

Bicorona elegans. Millard 1966a

Coryne pusilla. Warren 1908. ?Millard & Bouillon 1974.

Sarsia eximia. Millard 19596, 1966a

As Coryne sp. Millard 1957.

Sphaerocoryne bedoti. Millard & Bouillon 1974.

As Clavatella multitentaculata. Warren 1908.

Family Cladonemidae

Staurocladia vallentini. Millard 1966a

As Cnidonema capensis. Gilchrist 1919

Family Solanderiidae

Solanderia atrorubens. (Doubtful species)

As Dehitella atrorubens. Brazier 1887

Solanderia labyrinthica. (Doubtful species)

As Ceratella labyrinthica. Hyatt 1877

Solanderia minima. Millard & Bouillon 1974

Solanderia procumbens. Millard 1966a

As Ceratella procumbens. Carter 1873

As Ceratella spinosa. Carter 1873

As Solanderia atrorubens. Marshall 1892

Solanderia rugosa. Marshall 1892. (Doubtful species)

Family Asyncorynidae

Asyncoryne ryniensis. Warren 1908

472 ANNALS OF THE SOUTH AFRICAN MUSEUM

Family Cladocorynidae

Cladocoryne floccosa. Warren 1908. Millard 1959a. Millard & Bouillon 1974

Family Zancleidae

Zanclea sp. Millard & Bouillon 1974

Family Clavidae

Clava sp. Millard 1966a

Corydendrium parasiticum. Millard 1959a. Millard & Bouillon 1974

Merona cornucopiae. Millard 1966a

Rhizogeton nudum. Millard & Bouillon 1974

Turritopsis nutricula. Millard & Bouillon 1974

Family Eudendriidae

Eudendrium angustum. Warren 1908

Eudendrium %antarcticum. Stechow 1925a. Millard 1957

Eudendrium capillare. Millard & Bouillon 1974

As Eudendrium parvum. Warren 1908

As Eudendrium ?parvum. Millard 1959a

Eudendrium carneum. Millard 1959a

Eudendrium deciduum. Millard 1957, 1966a

Eudendrium motzkossowskae. Millard & Bouillon 1974

Eudendrium ramosum. Millard 1966a. Millard & Bouillon 1974

As Eudendrium ?capillare. Millard 1966a

* Fudendrium ritchiei sp. nov.

As Eudendrium annulatum (?). Ritchie 1909

As Eudendrium ?carneum. Millard 1966a

Family Bougainvilliidae

Bimeria fluminalis. Millard 1959a

Bimeria rigida. Warren 1919a

Bimeria vestita. Millard 1966a, 1968

As Leuckartiara vestita f. nana. Vervoort 19466

Bougainvillia macloviana. Jaderholm 1923a. Millard 1959b, 1966a

Bougainvillia meinertiae. Jaderholm 1923a

Bougainvillia ?ramosa. Stechow 1925a. Millard 1959b

As Bougainvillia sp. Millard 1966a, 1968

Clavopsella navis

As Rhizorhagium navis. Millard 1959b

Dicoryne conferta. Millard 1966a

Rhizorhagium robustum. Millard 1966a

As Parawrightia robusta. Warren 1907a

Family Hydractiniidae

*Clavactinia multitentaculata sp. nov.

As Hydractinia sp. Millard 1968

Aydractinia altispina. Millard 1955, 1957, 1966a

2As Hydractinia sp. Broch 1914

Hydractinia canalifera. Millard 1957

Hydractinia diogenes. Millard 1959a. Millard & Bouillon 1974

Hydractinia kaffraria. Millard 1955, 1959a, 1966a

* Hydractinia marsupialia sp. nov.

As Podocoryne carnea. Ritchie 19076. Millard 1966a

2As Hydractinia parvispina. Vanhoffen 1910

As Hydractinia carnea. Millard 1957

Hydractinia pacifica. Stechow 1925a. (Doubtful record)

Hydrocorella africana. Stechow 1921c, 1923b, 1925a. Millard 1957, 1966a. 1968

?Stylactis siphonis. (Doubtful species)

As Stylactella siphonis. Stechow 19216

As Halerella siphonis. Stechow 1925a

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 473

Family Cytaeidae

Cytaeis nassa. Millard & Bouillon 1974

As Podocoryne nassa. Millard 1959a

Family, Pandeidae

Hydrichthys boycei. Warren 1916. Millard 1959a

Leuckartiara octona. Millard 1957. Millard 1966a

As Perigonimus vestitus f. radicans. Vanhoffen 1910.

THECATA

Family Campanulinidae

Aequorea africana. Millard 1966a. Millard & Bouillon 1974

Calicella oligista. Stechow 1925a

Egmundella amirantensis. Millard & Bouillon 1974

*Tineolaria gravierae sp. nov.

As Lineolaria sp. Millard & Bouillon 1974

Lovenella chiquitita. Millard 1957, 1959b, 1966a, 1968

Modeeria rotunda

As Stegopoma fastigiata. Millard 1958

As Stegopoma fastigiatum. Millard 1967, 1968

Opercularella sp. Vervoort 19666

Phialella turrita

As Campanulina turrita. Vanhoffen 1910

Family Haleciidae

Halecium beanii. Stechow 1925a. Millard 1957, 1958, 1966a, 1968. Vervoort 19665

Halecium delicatulum. Hartlaub 1905. Millard 1966a, 1968

As Halecium parvulum, including var. magnum. Millard 1957

Halecium dichotomum. Allman 1888. Stechow 1925a. Millard 1957, 1966a, 1968

+ Halecium dyssymetrum

Halecium halecinum. Ritchie 1907b. Millard 1966a. Millard & Bouillon 1974

Halecium inhacae. Millard 1958. Millard & Bouillon 1974

Halecium lankesteri. Millard 1968. Millard & Bouillon 1974

Halecium ?muricatum. Millard 1966a, 1968

Halecium sessile. Vervoort 19666

Halecium tenellum. Stechow 1925a. Millard 1957, 1966a, 1968. Vervoort 1966b. Millard &

Bouillon 1974

Hydrodendron caciniformis. Millard 1957

Hydrodendron cornucopia. Millard 1973

As Zygophylax cornucopia. Millard 1955, 1957, 1964, 1968

Hydrodendron gardineri. Millard & Bouillon 1974

Hydrodendron gracilis. Millard 1973

As Zygophylax enigmatica. Millard 1964

Hydrodendron sympodiformis. Millard & Bouillon 1974

Family Lafoeidae

Acryptolaria conferta. Millard 1968

As Acryptolaria conferta conferta. Millard 1964

As Acryptolaria conferta australis. Millard 1964, 1967

Acryptolaria rectangularis. Millard 1967, 1968

As Acryptolaria angulata. Vervoort 19666

+ Cryptolarella abyssicola

+ Cryptolaria pectinata

Filellum antarcticum. ?Stechow 1925b. Millard 1964 (pp)

Filellum ?serpens. Stechow 1925a

As Reticularia serpens. Millard 1957.

Filellum serratum. Millard 1967, 1968

As Filellum ?antarcticum. Millard 1958, 1964 (pp)

474 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hebella dispolians

As Lafoea dispolians. Warren 1909.

Hebella furax. Millard 1957, 1964. Millard & Bouillon 1974.

Hebella parvula. Stechow 19235.

Hebella scandens. Stechow 19196. Millard 1957, 1958, 1964, 1968. Millard & Bouillon 1974.

As Lafoea scandens. Warren 1908.

As Hebellopsis scandens. Stechow 1925a

As Hebella urceolata. Millard 1964

Lafoea benthophila. Vervoort 19665

Lafoea dumosa. Stechow 1925a

Lafoea fruticosa. Stechow 1925a. Millard 1964, 1967, 1968.

As Lafoea gracillima. Vervoort 19666

Scandia mutabilis. Millard 1957, 1958, 1964. Millard & Bouillon 1974.

As Lafoea magna. Warren 1908

Zygophylax africana. Stechow 19236. Millard 1964, 1968.

+Zygophylax ?antipathes

Zygophylax armata. Millard 1964, 1967, 1968.

Zyzophylax ?biarmata. Millard 1958, 1968.

Zygophylax geminocarpa. Millard 1958.

Zygophylax ?geniculata. Millard 1968.

Zygophylax infundibulum. Millard 1958, 1968

Zygophylax sibogae. Millard 1964

Family Campanulariidae

Campanularia africana

As Campanularia tincta. Warren 1908.

Campanularia crenata. Millard & Bouillon 1974

Campanularia ?delicata. Millard & Bouillon 1974

As Campanularia ?crenata. Millard 1958

Campanularia hincksii. Millard 1966a

Campanularia integra. Billard 1907a. Millard 1957, 1958, 1966a. Millard & Bouillon 1974

As Campanularia caliculata. Warren 1908

As Clytia compressa. Vanhoffen 1910

?As Campanularia gracilis. Stechow 1925a

Campanularia laminacarpa. Millard 1966a, 1968. Millard & Bouillon 1974

?As Campanularia tincta. Jaderholm 1923a

?As Campanularia africana. Stechow 1925a

Campanularia morgansi. Millard 1957, 1958, 1966a, 1968. Millard & Bouillon 1974

Campanularia pecten. Gow & Millard 1975.

As Campanularia ?mollis. Millard 1966a.

Campanularia roberti. Gow & Millard 1975

Clytia gravieri. Millard & Bouillon 1974

As Laomedea striata. Kramp 1921

As Clytia serrata. Millard 1958

Clytia hemisphaerica. Millard 1966a, 1968. Millard & Bouillon 1974

As Clytia raridentata. Vanhoffen 1910

As Clytia gracilis. Stechow 1925a. Millard 1957, 1958

As Thaumantias raridentata. Stechow 1925a

As Clytia johnstoni. Millard 1958

Clytia hummelincki. Millard 1966a

Clytia latitheca. Millard & Bouillon 1974

Clytia paradoxa

As Eucalix paradoxus. Stechow 19236, 1925a

Clytia paulensis. Stechow 1925a. Millard 1966a, 1968. Millard & Bouillon 1974

?As Clytia (?) ulvae. Stechow 1925a

Clytia warreni

As Clytia elongata. Warren 1908

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 475

Eulaomedea calceolifera

As Laomedea calceolifera. Stechow 1925a

As Laomedea angulata. Millard 19596

Gonothyraea loveni

As Laomedea loveni. Millard 1959b .

Obelia bicuspidata. Millard 1958, 19596, 21968

Obelia dichotoma. Millard 1957, 1958, 19596, 1966a, 1968

As Obelia dubia. Vanhoffen 1910. Stechow 1925a

Obelia geniculata. Ritchie 1909. Broch 1914. Stechow 1925a. Millard 1957, 19595, 1966a

Family Syntheciidae

Hincksella corrugata. Millard 1958. Millard & Bouillon 1974

Hincksella cylindrica pusilla. Millard 1964

Hincksella echinocarpa. Millard 1967

Synthecium dentigerum. Millard 1964

Synthecium elegans. Millard 1957, 1958, 1964. Millard & Bouillon 1974

As Synthecium subyventricosum. Stechow 1925a

Synthecium hians. Millard 1957, 1964, 1968

Family Sertulariidae

Abietinaria abietina

As Sertularia abietina. Busk 1851. (Doubtful species)

Abietinaria laevimarginata. Millard & Bouillon 1974

As Sertularia linealis. Warren 1908. Millard 1958

Amphisbetia maplestonei

As Sertularia bidens. Warren 1908. Stechow 1912

As Odontotheca bidens. Stechow 1919b

As Amphisbetia bidens. Millard 1957, 1958, 1964

Amphisbetia minima. Millard 1957, 1958, 1964. Millard & Bouillon 1974

As Sertularia minima. Allman 1886

As Sertularia crinoidea. Allman 1886

Amphisbetia operculata. Stechow 1925a. Millard 1957, 1958, 1964, 1968

As Dynamena operculata. Krauss 1837

As Sertularia operculata. Busk 1851. Jaderholm 1903, 1917, 1923a. Warren 1908. Ritchie

1909. ?Stechow 1912. Vervoort 19465

As Sertularia aperta. Allman 1886

As Odontotheca operculata. Broch 1914. Stechow 19195

Calamphora campanulata

As Sertularella campanulata. Warren 1908

Crateritheca acanthostoma. Millard 1964

2As Dynamena pluridentata. Kirchenpauer 1864

As Sertularia acanthostoma. Warren 1908

As Stereotheca acanthostoma. Millard 1958

Dictyocladium coactum. Stechow 1923b. Millard 1957, 1964

Diphasia attenuata

As Sertularia rosacea. Busk 1851. (Doubtful species)

Diphasia bipinnata. Allman 1886. (Doubtful species)

Diphasia digitalis. Millard & Bouillon 1974

| Diphasia heurteli

Diphasia nigra

As Sertularia nigra. Busk 1851. (Doubtful species)

Diphasia tetraglochina. Millard 1964. Millard & Bouillon 1974

Dynamena cornicina. Millard 1964. Millard & Bouillon 1974

Dynamena crisioides. Millard 1958, 1964. Rees & Thursfield 1965. Millard & Bouillon 1974

As Thuiaria tubuliformis. Warren 1908

As Dynamena tubuliformis. Stechow 1919a

Dynamena obliqua. Millard 1958. Millard & Bouillon 1974

Dynamena pumila. Krauss 1837. (Doubtful species)

476 ANNALS OF THE SOUTH AFRICAN MUSEUM

Dynamena quadridentata. Vervoort 19466. Millard 1958, 1964. Millard & Bouillon 1974

As Pasythea quadridentata. Warren 1908

Hydrallmania falcata

As Plumularia falcata. Busk 1851. (Doubtful species)

Idiellana pristis. Millard 1968. Millard & Bouillon 1974

Parascyphus simplex. Millard 1968

Salacia articulata. Stechow 1925a. Millard 1957, 1958, 1964, 1968

As Thuiaria ellisii. Busk 1851

As Thuiaria persocialis. Allman 1876

As Thuiaria personalis. Kirchenpauer 1884

As Thuiaria articulata. Kirchenpauer 1884. Marktanner-Turneretscher 1890. Ritchie 1909.

Broch 1914

As Thuiaria pectinata. Allman 1888. Ritchie 19075

As Dymella articulata. Vervoort 19466. Stechow 1923c

+ Salacia desmoides

Salacia disjuncta. Millard 1964

Sertularella africana. Stechow 19196, 1923c. Millard 1957, 1964

As Sertularella fusiformis. Warren 1908

Sertularella agulhensis. Millard 1964

+ Sertularella annulaventricosa

As Sertularella tenella. Hartlaub 1901a (pp)

As Sertularella capensis delicata. Millard 1964

Sertularella arbuscula. Leloup 1934. Stechow 1925a. Millard 1957, 1958, 1964, 1968

As Sertularia 2arbuscula. Busk 1851

As Sertularia polyzonias. Busk 1851 (pp.)

As Sertularella arborea. Kirchenpauer 1884. Marktanner-Turneretscher 1890. Ritchie

1907b. Stechow 1912. Jaderholm 1917

As Sertularella crassipes. Allman 1886

As Sertularella cuneata. Allman 1886

As Sertularella tumida. Warren 1908

Sertularella capensis. Millard 1957, 1964

Sertularella congregata. Millard 1964

Sertularella diaphana. Millard 1958, 1968

Sertularella dubia magna. Millard 1958, 1964, 1968

Sertularella flabellum. Stechow 1925a. Millard 1957, 1958, 1964, 1968

As Thecocladium flabellum. Allman 1888

Sertularella fusiformis. Millard 1957, 1964

As Sertularella lineata. Stechow 19236

Sertularella gayi. Jaderholm 1923a

As Sertularia polyzonias, var. 8. Johnston 1838

As Sertularia polyzonias. Busk 1851 (pp.). (Doubtful species)

Sertularella gilchristi. Millard 1964

Sertularella goliathus. Stechow 19236. Millard 1957, 1964

Sertularella leiocarpa. Vervoort 19666. Millard 1968

Sertularella mediterranea mediterranea. Millard 1957, 1958, 1961

As Sertularella polyzonias. Warren 1908. ?Stechow 1912

Sertularella mediterranea asymmetrica. Millard 1958, 1964. Millard & Bouillon 1974

Sertularella megista. Stechow 19236. Millard 1957, 1964, 1967, 1968

As Sertularella polyzonias, f. robusta. Kirchenpauer 1884

As Sertularella sp. Millard 1958

Sertularella natalensis. Millard 1968

Sertularella polyzonias polyzonias. Kirchenpauer 1884. Millard 1957, 1958, 1961, 1964, 1968

As Sertularella polyzonias f. gracilis. Kirchenpauer 1884

Sertularella polyzonias falsa

As Sertularella falsa. Millard 1957, 1964

Sertularella polyzonias gigantea. Stechow 1925a

Sertularella polyzonias xantha

As Sertularella xantha. Stechow 1923b, 1925a. Millard 1957, 1964, 1967, 1968

As Sertularella longa. Stechow 19236

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 477

Sertularella pulchra. Stechow 1923b. Millard 1964

Sertularella striata. Stechow 1923a, 1925a. Millard 1964

Sertularia argentea. Busk 1851. (Doubtful species)

Sertularia distans. Millard & Bouillon 1974

As Sertularia distans var. gracilis. Millard*1957, 1958

As Sertularia distans gracilis. Millard 1964, 1968

Sertularia ligulata. Millard 1958. Millard & Bouillon 1974

Sertularia longa. Millard & Bouillon 1974

As Sertularia linealis var. longa. Millard 1958

As Sertularia linealis. Millard 1968

Sertularia marginata. Millard 1957, 1964. Millard & Bouillon 1974

Sertularia turbinata. Millard 1958, 1964. ?Rees & Thursfield 1965. Millard & Bouillon 1974

As Sertularia loculosa. Warren 1908

As Sertularia acuta. Millard 1958

Stereotheca elongata. Millard 1968

As Sertularia elongata. Jaderholm 1917

Symplectoscyphus arboriformis. Millard 1964, 1968

As Sertularia polyzonias. Busk 1851 (pp.)

As Sertularella arboriformis. Stechow 1912

Symplectoscyphus filiformis

As Sertularella filiformis var. reticulata. Ritchie 1907b. (Doubtful species)

Symplectoscyphus indivisus. Millard 1961. (Doubtful species)

Symplectoscyphus johnstoni

2As Sertularia gaudichaudi. Busk 1851. (Doubtful species)

Symplectoscyphus macrogonus. Millard 1957, 1964

Symplectoscyphus paulensis. Millard 1967

Symplectoscyphus secundus

As Sertularella secunda. Kirchenpauer 1884

As Sertularella limbata. Allman 1886

Symplectoscyphus unilateralis

2As Sertularia unilateralis. Busk 1851. (Doubtful species)

Thuiaria doliolum. Kirchenpauer 1884. (Doubtful species)

Thyroscyphus aequalis. Warren 1908. Millard 1958, 1964, 1968. Millard & Bouillon 1974

As Thyroscyphus regularis. Jaderholm 1923a. Stechow 1925a

Thyroscyphus fruticosus. Millard 1958. Millard & Bouillon 1974

Family Plumulariidae

Subfamily Halopterinae

Antennella africana. Millard 1957, 1962, 1968

As Antenella quadriaurita forma africana. Broch 1914

As Antenella africana. Stechow 1923a, 1925a

Antennella secundaria. Millard 1958, 1962, 1968. Millard & Bouillon 1974

As Antennella natalensis. Warren 1908

As Antenella secundaria. Stechow 1925a

Corhiza bellicosa. Millard 1962

Corhiza mortenseni. Millard 1968

Corhiza pannosa. Millard 1962, 1968

Corhiza scotiae. Millard 1962, 1968

As Antennopsis scotiae. Ritchie 1907b, 1909. Millard 1957

Corhiza valdiviae

As Heteroplon valdiviae. Stechow 1923a

As Thecocaulus(?) valdiviae. Stechow 1925a

As Halopteris valdiviae. Millard 1957, 1962

|Gattya conspecta

Gattya heurteli. Millard 1968

As Paragattya heurteli. Millard 1958

As Paragattya intermedia. Millard 1958

478 ANNALS OF THE SOUTH AFRICAN MUSEUM

Gattya humilis. Allman 1886. Millard 1961, 1962

As Paragattya intermedia. Warren 1908, 19195. Stechow 1925a. Millard 1957

(non Millard 1958)

7Gattya multithecata

Halopteris gemellipara. Millard 1962

Halopteris glutinosa. Millard 1958, 1962, 1968. Millard & Bouillon 1974

As Plumularia (Heteroplon) glutinosa. Stechow 1925a

Halopteris polymorpha. Vervoort 19666. Millard & Bouillon 1974

* Halopteris pseudoconstricta sp. nov.

As Halopteris constricta. Millard 1957, 1962

* Halopteris rostrata sp. nov.

Halopteris tuba. Millard 1961, 1962, 1968

As Plumularia tuba. Kirchenpauer 1876

As Acladia africana. Marktanner-Turneretscher 1890

As Heteroplon jaederholmi. Stechow 1912

As Plumularia Jaderholmi. Jaderholm 1917

As Plumularia (Heteroplon) africana. Stechow 1925a

As Thecocaulus tuba. Leloup 1939

Monostaechas faurei. Millard 1958, 1968

Monostaechas natalensis. Millard 1958, 1962, 1968

Monostaechas quadridens. Millard & Bouillon 1974

Schizotricha frutescens

As Aglaophenia frutescens. Krauss 1837

Schizotricha simplex. Warren 1914. Millard 1962

Family Plumulariidae

Subfamily Kirchenpaueriinae

Kirchenpaueria irregularis: Millard & Bouillon 1974

As Plumularia irregularis. Millard 1958

Kirchenpaueria pinnata. Vervoort 1946b. Millard 1957, 19596, 1962, 1968

?As Plumularia gaymardi. Kirchenpauer 1876

As Plumularia unilateralis. Ritchie 19076

As Plumularia pinnata. Ritchie 19076

As Plumularia echinulata. Ritchie 1907b, 1909

As Plumularia pinnata, f. typica. Broch 1914

Kirchenpaueria triangulata. Millard 1962, 1967, 1968. Vervoort 19665

Oswaldella nova. Millard 1962. Millard & Bouillon 1974

As Kirchenpaueria adhaerens. Millard 1958

Pycnotheca mirabilis. Millard 1957, 1958 (including var. warreni). Millard & Bouillon 1974

As Kirchenpaueria mirabilis. Warren 1908

Family Plumulariidae

Subfamily Plumulariinae

Dentitheca bidentata. Millard & Bouillon 1974

Nemertesia antennina. Stechow 1912

As Nemertesia antennina irregularis. Vervoort 19665

Nemertesia ciliata. Millard 1962, 1968

Nemertesia cymodocea. Millard 1957, 1962, 1968

As Antennularia cymodocea. Busk 1851

As Nemertesia johnstoni. ?Kirchenpauer 1876

As Nemertesia decussata. Kirchenpauer 1876

As Antennularia decussata. Marktanner-Turneretscher 1890

As Antennularia hartlaubi. Ritchie 19076

Nemertesia ramosa. Millard 1957, 1962, 1967, 1968. Vervoort 19665

As Antennularia ramosa. Busk 1851

Plumularia antonbruuni. Millard 1967

Plumularia filicaulis. Leloup 1934. Millard 1958, 1962. Millard & Bouillon 1974

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 479

Plumularia lagenifera. Broch 1914. Millard 1957, 1962

2As Aglaophenia gaimardi. Lamouroux 1824

As Plumularia lagenifera, var. septifera. Ritchie 1909

* Plumularia mossambicae sp. nov.

Plumularia obliqua. Millard & Bouillon 1974 .

Plumularia pennycuikae. Millard & Bouillon 1974

Plumularia pulchella. Millard 1957, 1962

As Plumularia (Monotheca) flexuosa. Stechow 1925a

Plumularia setacea. Broch 1914. Stechow 1925a. Millard 1957, 1958, 1959b, 1962, 1968.

Vervoort 19665. Millard & Bouillon 1974

Plumularia spinulosa. Warren 1908. Millard 1962

As Plumularia spinulosa, var. obtusa. Millard 1957

As Plumularia spinulosa, var. typica. Millard 1958

Plumularia strictocarpa. Millard & Bouillon 1974

Plumularia warreni. Millard 1958. Millard & Bouillon 1974

As Plumularia tenuis. Warren 1908

Plumularia wasini. Millard 1962, 1968. Millard & Bouillon 1974

Family Plumulariidae

Subfamily Aglaopheniinae

Aglaophenia alopecura. Kirchenpauer 1872. Marktanner-Turneretscher 1890. Stechow 1912.

(Doubtful species)

Aglaophenia attenuata. Allman 1883. (Doubtful species)

Aglaophenia cupressina. Millard & Bouillon 1974

Aglaophenia holubi. Leloup 1934. (Doubtful species)

Aglaophenia latecarinata. Millard 1958, 1962

Aglaophenia pluma dichotoma. Millard 1962, 1968

As Aglaophenia dichotoma. Kirchenpauer 1872. Ritchie 1907b. Stechow 1925a

As Aglaophenia pluma, var. dichotoma. Millard 1957

Aglaophenia pluma parvula. Millard 1962, 1968

As Aglaophenia conferta. ?Kirchenpauer 1872

As Aglaophenia heterodonta. Jaderholm 1903. Ritchie 1909 (pp.)

As Aglaophenia parvula. Stechow 1925a. Vervoort 19465

As Aglaophenia pluma, var. parvula. Millard 1957, 1958

Aglaophenia pluma pluma. Millard 1968

As Aglaophenia pluma. ?Krauss 1837. Broch 1914. Vervoort 19465

As Aglaophenia chalarocarpa. Allman 1886. Warren 1908

As Aglaophenia pluma, var. typica. Millard 1957, 1958

Aglaophenia pusilla. Kirchenpauer 1872. (Doubtful species)

Aglaophenia tubulifera. Kirchenpauer 1872

As Plumularia cristata. Busk 1851. (Doubtful species)

*Cladocarpus crepidatus sp. nov.

Cladocarpus distomus. Vervoort 1966b. Millard 1967, 1968. Vervoort 1972

Cladocarpus dofleini. Vervoort 19665

Cladocarpus inflatus. Vervoort 1966)

Cladocarpus leloupi. Millard 1962

As Cladocarpus flexilis. Leloup 1939

Cladocarpus lignosus. Kirchenpauer 1872. Stechow 1923c, 1925a. Millard 1962

As Plumularia sp. Busk 1851

Cladocarpus millardae. Vervoort 19666

Cladocarpus sinuosus. Vervoort 19665

Cladocarpus tenuis. Vervoort 1966)

*Cladocarpus unicornus sp. nov.

Cladocarpus valdiviae. Stechow 19236

Gymnangium africanum

As Halicornaria africana. Millard 1958, 1968

Gymnangium allmanii

As Halicornaria allmani. Millard 1968

480 ANNALS OF THE SOUTH AFRICAN MUSEUM

Gymnangium arcuatum. Rees & Thursfield 1965

As Aglaophenia arquata. Krauss 1837

As Aglaophenia arcuata. Kirchenpauer 1872. Broch 1914

As Halicornaria arcuata. Stechow 1912. Millard 1958 (ncluding var. epizootica), 1962

(including subsp. epizootica)

Gymnangium exsertum

As Halicornaria exserta. Millard 1962 (including subsp. epizootica)

Gymnangium ferlusi

As Halicornaria ferlusi. Millard 1962

Gymnangium gracilicaule gracilicaule. Millard & Bouillon 1974

As Halicornaria gracilicaulis. Millard 1967

As Halicornaria gracilicaulis gracilicaulis. Millard 1968

Gymnangium gracilicaule lignosum. Millard & Bouillon 1974

As Halicornaria gracilicaulis. Millard 1958

Gymnangium hians

As Halicornaria hians. Millard 1958

Gymnangium longirostre

As Halicornaria longirostris. Millard 1961

Gymnangium montagui

As Aglaophenia pennatula. ?Krauss 1837

As Plumularia pennatula. ?Busk 1851

As Halicornaria allmanii var. Marktanner-Turneretscher 1890

Lytocarpus filamentosus. Broch 1914. Jaderholm 1917. Warren 1919b. Millard 1957, 1958,

1961, 1962, 1968. Rees & Thursfield 1965

As Aglaophenia fusca. Kirchenpauer 1872. Marktanner-Turneretscher 1890

As Aglaophenia patula. Kirchenpauer 1872

As Aglaophenia ligulata. Kirchenpauer 1872

As Lytocarpus patulus. Marktanner-Turneretscher 1890

As Halicornaria segmentata. Warren 1908

As Nematophorus plumosus. Stechow 1923a

As Aglaophenia plumosa. Stechow 1925a

Lytocarpus philippinus. Millard 1958, 1968. Millard & Bouillon 1974

Lytocarpus phoeniceus. Millard 1968

Thecocarpus brevirostris. Millard 1968

As Aglaophenia brevirostris. ?Kirchenpauer 1872

As Aglaophenia vitiana. Billard 1907a

Thecocarpus delicatulus. Millard & Bouillon 1974

Thecocarpus flexuosus flexuosus. Millard 1962

As Aglaophenia (?) bifida. Stechow 1923b

As Thecocarpus giardi. Vervoort 19466. Millard 1957, 1958

Thecocarpus flexuosus plumiferus. Millard 1962, 1968

As Aglaophenia plumifera. Kirchenpauer 1872

Thecocarpus flexuosus solidus. Millard 1962, 1968

As Thecocarpus giardi, var. solidus. Millard 1958

Thecocarpus flexuosus umbellatus. Millard 1962

Thecocarpus formosus. Billard 1907a. Stechow 1912. Broch 1914. Vervoort 19465. Millard

1958, 1962, 1968. Rees & Thursfield 1965

As Plumularia formosa. Busk 1851

As Aglaophenia formosa. Kirchenpauer 1872. Marktanner-Turneretscher 1890

As Aglaophenia parasitica. Warren 1908.

LIMNOMEDUSAE

Family Moerisiidae

Ostroumovia inkermanica. Millard 1970

Family Proboscidactylidae

Proboscidactyla sp. Millard & Bouillon 1974

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 481

RECORDS OF HYDROID MEDUSAE FROM THE SOUTH AFRICAN REGION

(between 20-40°S and 10-40°E)

(UCT: University of Cape Town; RU: Rhodes University)

ATHECATA (Anthomedusae) . Distribution lat./long.

TUBULARIIDAE

Ectopleura dumortieri (van Beneden, 1844) 26/15

Euphysora furcata Kramp, 1948 30/13, 35/18

Paragotoea bathybia Kramp, 1942 35/18

CORYNIDAE

Dipurena halterata (Forbes, 1846) UCT record: 33/18

Sarsia gracilis Browne, 1902 34/18

Sarsia sp. VICE record: 33/18

CLADONEMIDAE

Staurocladia vallentini (Browne, 1902) 34/18. UCT records: 26/15, 33/18

CLAVIDAE

Oceania armata KOlliker, 1853 25/36

HYDRACTINIIDAE

Podocoryne carnea M. Sars, 1846 Position not recorded

BOUGAINVILLIIDAE

Bougainvillia fulva Agassiz & Mayer, 1899 31/30, 25/36, 24/37, 24/38

B. macloviana Lesson, 1836 UCT record: 33/18

B. platygaster (Haeckel, 1879) 34/26, 31/29, 25/36

Kollikerina multicirrata (Kramp, 1928) 31/30, 29/32

CYTAEIDAE

Cytaeis tetrastyla Eschscholtz, 1829 DS SONWiCiml records) 33/285 31/29. 30/5,

30/31, 30/32, 29/31

PANDEIDAE

Annatiara affinis (Hartlaub, 1913) 34/16

Halitholus intermedius (Browne, 1902) SSS s/29

Leuckartiara annexa Kramp, 1957 30/32, 24/38

L. gardineri Browne, 1916 31/30, 29/31, 24/38

L. octona (Fleming, 1823) 31/30, 29/32, 25/36

Neoturris papua (Lesson, 1843) 31/30, 25/36

N. pileata (Forskal, 1775) 26/12

Octotiara russelli Kramp, 1953 31/30

Pandea conica (Quoy & Gaimard, 1824) 33/16, 34/15, 34/26, 25/36

CALYCOPSIDAE

Bythotiara murrayi Gimnther, 1903 26/12

Calycopsis bigelowi Vanhoffen, 1911 33/155 33/116, 34/15

C. chuni Vanhoffen, 1911 34/26, 25/36

Heterotiara anonyma Maas, 1905 30/13

H. minor Vanhoffen, 1911 36/36, 31/29, 25/36, 24/37

THECATA (Leptomedusae)

LAODICEIDAE

Chromatonema rubrum Fewkes, 1882 33/16, 34/15

Laodicea indica Browne, 1905 36/21

L. undulata (Forbes & Goodsir, 1851) 33/15. Wie T record: 2729/31

MITROCOMIDAE

Cosmetirella davisi (Browne, 1902) 26/15, 35/18

Mitrocoma minervae Haeckel, 1879 Position not recorded

Mitrocomella grandis Kramp, 1965 Position not recorded

482 ANNALS OF THE SOUTH AFRICAN MUSEUM

AEQUOREIDAE

Aequorea aequorea (Forskal, 1775) 22/13, 36/16, 31/30, 29/32. UCT record:

33/18

A. australis Uchida, 1947 36/21, 29/32, 25/36

A. coerulescens (Brandt, 1838) 26/15, 29/32

A. conica Browne, 1905 29/31

* 4. macrodactyla (Brandt, 1838) 33/15, 33/16, 34/16, 35/18, 36/21, 31/30,

31/32, 29/32, 34/34, 25/36, 39/38

* 4. pensilis (Eschscholtz, 1829) 35/209 36/2129 /3129)/82

A. Sp. 33/15, 34/17, 35/17, 31/29, 24/39

Zygocanna vagans Bigelow, 1912 33/15, 34/15, 31/30, 29/32, 24/38

PHIALELLIDAE

Phialella falklandica Browne, 1902 UCT record: 33/18

LOVENELLIDAE

Cirrholovenia polynema Kramp, 1959 24/37

Eucheilota sp. 34/18

PHIALUCIIDAE

Phialucium carolinae (Mayer, 1900) 24/37

EIRENIDAE (including Eutimidae)

Eirene ceylonensis Browne, 1905 29/32

E. hexanemalis (Goette, 1886) 36/21, 29/32

E. menoni Kramp, 1953 29/32

E. palkensis Browne, 1905 29/31

Eutima levuca (Agassiz & Mayer, 1899) 29/31

Phialopsis diegensis Torrey, 1909 33/15, 34/16, 34/34, 36/36, 29/32

CAMPANULARIIDAE

Phialidium ?phosphoricum

(Péron & Lesueur, 1809) 34/18

P. simplex Browne, 1902 34/26

Obelia sp. 26/15, 34/18. UCT record: 33/18

LIMNOMEDUSAE

MOERISIIDAE

Ostroumovia inkermanica

(Paltschikowa-Ostroumowa, 1925) RU record: 27/32

PROBOSCIDACTYLIDAE

Proboscidactyla mutabilis (Browne, 1902) UCT record: 33/18

ACKNOWLEDGEMENTS

The author wishes to express thanks to the following institutions for the

loan of hydroid material for comparative examination:

The Royal Scottish Museum, Edinburgh

Zoologische Sammlung des Bayerischen Staates, Munich

Naturhistoriske Riksmuseet, Stockholm

Zoological Survey of India, Calcutta

The British Museum (Natural History), London

The Natal Museum, Pietermaritzburg

*Vanhoffen (1911, 1912) apparently included both A. macrodactyla and A. pensile under the

name of Mesonema coelum pensile. These records have been omitted.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 483

Help received from the following in identification of material other than

Hydroida is gratefully acknowledged:

Dr M. E. Thiel of the Hamburg Museum and the late Dr W. J. Rees of the British

Museum (Natural History): medusae

Professor J. H. Day, University of Cape Town: polychaets

Dr B. Kensley, South African Museum: gastropods and decapods

The author is also indebted to many colleagues and students at the Uni-

versity of Cape Town and the South African Museum for collecting and

preserving interesting specimens whenever the opportunity offered.

Permission to reproduce diagrams of species not available to the author

has been granted by the following:

Naturhistorisches Museum, Vienna (Annln Naturh. Mus. Wien)

Universitetets Zoologiske Museum, Copenhagen (Galathea Rep.)

The Editor, Vidensk. Meddr dansk naturh. Foren.

Gustav Fischer Verlag, Stuttgart (Wiss. Ergebn. dt. Tiefsee-Exped. ‘ Valdivia’)

Walter de Gruyter & Co., Berlin (Dr. Siidpol.— Exped.)

Naturshistoriska Museet, Goteborg (Medd. Goteborg Mus. Zool.)

Co. of Biologists, University of Cambridge (Quart. J. microsc. Sci.)

Natal Museum, Pietermaritzburg (Ann. Natal Mus.)

University of Tokyo (J. Coll. Sci. imp. Univ. Tokyo)

Institut Royal des Sciences Naturelles de Belgique (Bull. Mus. r. Hist. nat. Belg.)

ADDENDUM

Family Plumulariidae

Subfamily Aglaopheniinae

Cladocarpus paries * sp. nov.

Fig. 143

Holotype: SAM-H1914: off East London, 33°25’S/27°29’E, 70 m, 23/1/75.

Description. One branching stem 75 mm high. Hydrorhiza a thickened mat

5 mm wide, flattened on under side and detached from some hard surface.

Stem thick and strongly fascicled, 1,5 mm thick at base, branching and

rebranching in one plane; bearing alternate hydrocladia from an axial tube.

Larger branches fascicled almost to end. Axial tube, where exposed, divided

into regular internodes by straight nodes, each internode bearing one hydro-

cladial apophysis and two nematothecae, one anterior axillary and one proximal

and anterior. Peripheral tubes bearing longitudinal rows of nematothecae. The

two rows of hydrocladia in one plane.

Hydrocladium 2-3 mm in length and bearing up to eight hydrothecae.

First internode short and athecate, with one median nematotheca. Remaining

internodes thecate, each bearing one hydrotheca and three nematothecae, one

median inferior and two laterals. All nodes oblique. Two internodal septa in

* paries: the wall of a house.

484 ANNALS OF THE SOUTH AFRICAN MUSEUM

Fig. 143

Cladocarpus paries sp. nov. A, stem; B, anterior view of stem showing origins of hydrocladia;

C_D, parts of hydrocladia with hydrothecae; E, t.s. perisarc of hydrocladium showing

partition in hydrotheca (internode above, hydrotheca below).

Scale: A in cm, the rest in mm/10.

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 485

first internode; four or five in thecate internodes, three or four behind hydro-

theca and one proximal.

Hydrotheca deep and tubular, curved slightly outwards. Abcauline wall

with slight sigmoidal curvature, margin forming an angle of 40—50° with inter-

node. No transverse intrathecal septa, but a longitudinal septum attached to

centre of abcauline wall and stretching up to halfway across cavity. Margin

sinuated, with no distinct teeth, but sometimes with a low, rounded lobe on

each side. Abcauline edge thickened.

Median inferior nematotheca free from hydrotheca, short, reaching to just

above base of hydrotheca, bifurcated and with two terminal apertures, with a

third aperture on upper surface of undivided part; no opening into hydrotheca.

Lateral nematotheca bifurcated, with one terminal aperture on a long neck and

reaching well above thecal margin, a second opening on a shorter neck reaching

approximately to thecal margin and a third opening on mesial surface. Cauline

nematotheca sac-shaped, with one or two openings.

Gonothecae absent.

Measurements (mm)

Hydrocladium, first internode, length .. a: ae + .. 0,10—0,13

other internodes, length a bi eet ie Ee .-4 10323-0535

Hydrotheca, length oe ne ae ne a 8 .. 0,18-0,24

width at mouth 3 o nus a cs Le .. 0,10-0,11

width/length .. : uf re Me m5 Me .. 0,42-0,56

Lateral nematotheca, length oe a =n ae .. 0,13-0,19

Median nematotheca, length of free seat et hye des .. 0,03-0,05

Remarks. This species closely resembles Cladocarpus lignosus in general

appearance and form of the colony. It differs in the narrower, outwardly-curved

hydrotheca, in the absence of marginal teeth, and in the longer lateral nemato-

theca. The median partition in the hydrotheca is a unique feature distinguishing

it from all other species of Cladocarpus; it is widest at about the centre of the

hydrotheca, where it may reach halfway across the cavity, and narrows rapidly

above this to peter out below the thecal margin. The hydranth bulges onto

both sides of the partition.

Distribution. Endemic to South Africa.

Distribution in South Africa. The only record is the holotype recorded above.

33/27 (s)

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496 ANNALS OF THE SOUTH AFRICAN MUSEUM

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INDEX TO SCIENTIFIC TERMS

Abaxial, 18 Desmoneme, 20

Abcauline, 14 Diaphragm, 8, 14, 27, 31

Aboral tentacle, 8 * Dichotomous branching, 12

Acrocyst, 19, 20, 245 — sympodium, 12

Actinula, 20, 31 Dioecious, 20

Adaxial, 18

Adcauline, 14

Adnate, 14

Adradius, 17

Ectodermal statocyst, 18

Endodermal canals, 8, 27, 31

— statocyst, 18

s — lamella, 19

Alternate branching, 12 Boones tet 23

— hydrothecae, 15 ; j

: ? Epizootic, 22

Anchoring filaments, 7, 27 Bumedusoid: (3

Anisorhiza, 20 Burytele, 21

Annular thickening, 14, 200 Becca pore. 18

Annulation, 11

Anterior face, 15 Exumibrella, 16

Apical canal, 17 Fascicled stem, 11

— process, 17 Fasciculation, types in Plumulariidae, 326

Apophysis, 11 Fenestra, 231

Asexual reproduction, 22 Filiform tentacle, 9, 17

— — in Moerisiidae, 465 Fission, 22, 465

Athecate hydranth, 11 Fixed sporosac, 19

Atrichous isorhiza, 21 Flexuous stem, 239

Attachment disc, 7

Gastral cavity, 8

Auto-epizootic, 22, 326 Mes

Gastrozooid, 9

Basitrichous isorhiza, 21 Geniculate stem, 11, 200

Blastostyle, 9 Glutinant, 21

Blind caecum, 8, 231, 243 Gonad, 18

‘Branched’ tentacles, 18, 64 Gonophore, 11, 15

Branching, types, 11 Gonophore, types, 18

Budding, 22, 465 Gonotheca, 11, 15

Butt, 20 Gonozooid, 9

Caecum, blind, 8, 231, 243 Growth, types, 10

Campanulate hydrotheca, 14, 200 Haploneme, 20

Capitate tentacle, 9, 17 Helicoid sympodium, 12

Capsule, 20 Heteromedusoid, 19

Cauline hydrotheca, 15 Heteromerous hydrocladium, 327

— nematotheca, 15 Heteroneme, 20

Circular canal, 17 Heterotrichous anisorhiza, 20

Cirrus, 18 Hinge-joint, 22, 240, 327

Cnidocyst, 20 Hollow tentacle, 9, 17

Cnidome, 21 Homomerous hydrocladium, 327

Cnidocyst, see nematocyst Hydranth, 7, 8

Cnidophore, 21, 68, 78, 469 Hydrocaulus, 7

Coelenteron, 7 Hydrocladium, 14, 40, 325

Coenosarc, 7 Hydrophore, 58, 141

— naked, 16 Hydropore, 14, 241

Commensalism, 22 Hydrorhiza, 7

Commensals, list, 23 Hydrotheca, 11, 14

Contiguous hydrothecae, 240 Hydrotheca, types in Sertularella, 240

Coppinia, 16, 167 Hypostome, 8, 17

Corbula, 16, 329

Cordylus, 18 Incrusting hydrorhiza, 7

Internal skeleton, 16

Cryptomedusoid, 19 — teeth, 14, 242

Dactylozooid, 9 Internodal septum, 11

Depths, 4 Internode, 11

497

498

Interradius, 17

Intertentacular web, 9

Intrathecal septum, 14, 241

Isorhiza, 20

Lateral nematotheca, 15

Ligula, 244

Macrobasic eurytele, 21

— mastigophore, 21

Mamelon, 328

Marginal bulb, 17

— teeth, 14, 242

— tentacle, 17

— vesicle, 18

Marsupium, 20, 245

Mastigophore, 21

Measurements, 4

Meconidium, 202

Median inferior nematotheca, 15

Medusa, 6, 16

Medusae, South African records, 481

Merotrichous isorhiza, 21

Microbasic eurytele, 21

— mastigophore, 21

Moniliform tentacle, 8, 17

Monoecious, 20

Monopodial growth, 10, 11

Mouth, 7, 17

Naked coenosarc, 16

Nematocysts, 5, 20

—., Classification, 20

—., structure, 20

Nematophore, 10

Nematotheca, 15

Nematothecae, arrangement in Plumulari-

idae, 15, 327

—, names, 15

Nettle ring, 78

Node, 11

Ocellus, 18

Operculum, 14, 242

—, types in Campanulinidae, 127

Opposite branching, 12

— hydrothecae, 15

Oral lip, 17

— tentacle, 8, 17

Parasites, list, 23

Pedal disc, 7, 465

Pedicel, 14

Pedicellate hydrotheca, 14

Peduncle, 17

Penetrant, 21

Perisarc, 11

Perradius, 17

Phylactocarp, 16, 329

Pinnate branching, 12

Planula, 20

Podium, 11

ANNALS OF THE SOUTH AFRICAN MUSEUM

Podocyst, 22, 465

Polymorphism, 9

Polyp, 6, 7

Posterior face, 15

Pseudodiaphragm, 142

Pseudohydrotheca, 11, 90

Radial canal, 17, 27

Refringent nodules, 141

Regeneration, 22

Sarcostyle, 10, 327

Schizogeny, 22

Scorpioid sympodium, 12

Sense-organs, types, 18

Septum, internodal, 11

—, intrathecal, 14, 241

Sessile hydrotheca, 14

Skeleton, internal, 16

Solid tentacle, 9, 17

Spadix, 19

Spines, 20, 104

Spiral branching, 12

— zooid, 10

Sporosac, fixed, 19

Statocyst, 18

Statolith, 18

Stenotele, 21

Stiff stem, 239

Sting cell, see nematocyst

Stolon, 7

Stolonial colony, 10

Stolonization, 22, 465

Stomach, 17

Styloid, 19

Subalternate hydrothecae, 15

Subopposite hydrothecae, 15

Subumbrella, 16

Subumbrellar cavity, 17

Superior nematotheca, 15

Sympodial branching, 12

— growth, 11

Sympodium, 11, 12

Teeth, internal, 14, 242

—, marginal, 14, 242

Tentacle, 8

—, marginal, 17

Tentacles, types, 8

Tentaculozooid, 10

Thecate hydranth, 11

Trabecula, 16, 58

Tube, 20

Unfascicled stem, 11

Velum, 17

Villi, 8

Volvent, 20

Web, intertentacular, 9

Whorled branching, 12

INDEX TO SPECIES

Synonyms are printed in italics; names of families and subfamilies in capitals; pages with

figures in bold type. Only the main references are given.

abietina, Abietinaria, 247 — brevirostris, 480

—, Sertularia, 247 — chalarocarpa, 412

Abietinaria, 246 — conferta, 413

— abietina, 247 — cupressina, 408, 410

— laevimarginata, 246, 248 — delicatula, 455

abyssicola, Cryptolarella, 172, 173 — dichotoma, 413

—, Cryptolaria, 172 — filicula, 416

acanthostoma, Crateritheca, 253, 255 — flexuosa, 457, 458

—, Sertularia, 253 — formosa, 461

—, Stereotheca, 475 — frutescens, 478

Acladia, 349 — fusca, 447

— africana, 478 — gaimardi, 392

Acryptolaria, 168 — glutinosa, 352

— angulata, 171 — heterodonta, 413

— conferta, 169, 170 — holubi, 415

— pectinata, 174 — latecarinata, 409, 410

— rectangularis, 171, 173 — lignosa, 425

acuta, Sertularia, 312 — ligulata, 447

—, Tridentata, 312 — longirostris, 445

adhaerans, Kirchenpaueria, 376 — macgillivrayi, 408

aequalis, Cnidoscyphus, 321 — parasitica, 461

—, Thyroscyphus, 321, 322 — parvula, 413

Aequorea, 129 — patula, 447

— aequorea, 482 — pennatula, 446

— africana, 130, 131 — philippina, 449

— australis, 482 — phoenicea, 451

— coerulescens, 482 — pluma, 411

— conica, 482 — — dichotoma, 413, 414

— macrodactyla, 482 — — parvula, 413, 414

— pensilis, 482 — — pluma, 412, 414

— sp., 482 — — y. typica, 412

aequorea, Aequorea, 482 — plumifera, 460

AEQUOREIDAE, 129, 482 — plumosa, 447

affinis, Annatiara, 481 — pusilla, 416

africana, Acladia, 478 — tubulifera, 416

—, Aequorea, 130, 131 — vitiana, 454

—, Antennella, 331, 333 AGLAOPHENIINAE, 407

—, Campanularia, 204, 205 Aglaophenopsis, 416

—, Campanularia, 474 agulhensis, Sertularella, 279, 280

—, Halicornaria, 433 alatus, Cladocarpus, 418

—, Hydrocorella, Frontispiece, 116, 117 allmanii, Gymnangium, 434, 435

—, Plumularia, 359 —, Halicornaria, 434

—, Sertularella, 278, 280 — var., Halicornaria, 446

—, Zygophylax, 189, 191 alopecura, Aglaophenia, 415

africanum, Gymnangium, 433, 435 alternata, Plumularia, 352

Agastra, 203 altispina, Hydractinia, Frontispiece, 108, 110

— mira, 208 amirantensis, Egmundella, 131, 133

— rubra, 208 Amphicodon unicus, 32

Aglaophenia, 407 Amphisbetia, 247

— alopecura, 415 — bidens, 249

— arcuata, 436 — maplestonei, 248, 249

— arquata, 480 — minima, 248, 250

— attenuata, 415 — operculata, 251, 252

— bifida, 458 angulata, Acryptolaria, 171

499

500 ANNALS OF THE SOUTH AFRICAN MUSEUM

angulata, Laomedea, 223

angustum, Eudendrium, 79, 81

Annatiara affinis, 481

annexa, Leuckartiara, 481

annulatum, Eudendrium, 87

annulaventricosa, Sertularella, 279, 280

anonyma, Heterotiara, 481

antarctica, Lafoea, 177

—, Reticularia, 177

antarcticum, Eudendrium, 80, 81

—, Filellum, 176, 177

—, Filellum, 178

Antennella, 330

— africana, 331, 333

— natalensis, 332

— quadriaurita f. africana, 331

— secundaria, 332, 333

— serrata, 331

Antennellopsis, 330

antennina, Antennularia, 381

—, Nemertesia, 381, 382

—, Sertularia, 381

Antennopsis scotiae, 338

Antennularia, 381

— antennina, 381

— cymodocea, 384

— decussata, 384

— hartlaubi, 384

— irregularis, 381

— ramosa, 386

antipathes, Lictorella, 190

—, Sertularia, 190

—, Zygophylax, 190, 191

antonbruuni, Plumularia, 389, 391

aperta, Sertularia, 251

arborea, Sertularella, 476

arboriformis, Sertularella, 316

—, Symplectoscyphus, 315, 316

arbuscula, Sertularella, 280, 281

—, Sertularia, 281

arcta, Coppinia, 177

arcuata, Aglaophenia, 436

—, Halicornaria, 436

arcuatum, Gymnangium, 436, 439

argentea, Sertularia, 313

armata, Brucella, 192

—, Oceania, 481

—, Zygophylax, 192, 194

arquata, Aglaophenia, 480

articulata, Dymella, 273

—, Salacia, 272, 273

—, Sertularia, 273

—, Thuiaria, 273

Asyncoryne, 63

—ryniensis, 53, 63

ASYNCORYNIDAE, 63

atrorubens, Dehitella, 61

—, Solanderia, 61

attenuata, Aglaophenia, 415

—, Diphasia, 260

australis, Aequorea, 482

—, Pennaria, 41

bathybia, Paragotoea, 481

bathyzonatus, Cladocarpus, 418

beanii, Halecium, 144, 146

—, Thoa, 144

bedoti, Sphaerocoryne, 53, 54

bellicosa, Corhiza, 334, 336

benthophila, Lafoea, 185, 186

bethae, Ectopleura, 32, 33

betheris, Tubularia, 32

biarmata, Zygophylax, 193, 194

Bicorona, 49

— elegans, Frontispiece, 49, 50

bicuspidata, Laomedea, 226

—, Obelia, 226, 228

bidens, Amphisbetia, 249

—, Odontotheca, 475

—, Sertularia, 249

bidentata, Dentitheca, 380, 382

—, Plumularia, 380

bifida, Aglaophenia, 458

bigelowi, Calycopsis, 481

Bimeria, 91

— fluminalis, 91, 92

— rigida, 93, 94

— vestita, 94, 95

bipinnata, Diphasia, 260

Bougainvillia, 95

— fruticosa, 97

— fulva, 481

— macloviana, 96, 98, 481

— meinertiae, 97, 98

— muscus, 97

— platygaster, 481

— ramosa, 97, 98

— sp. 97

— vanbenedeni, 97

bougainvillii, Cyanaea, 96

BOUGAINVILLUDAE, 88, 481

boycei, Hydrichthys, 122, 124

Branchiaria, 28

Branchiocerianthus, 28

— imperator, 28, 29

brevirostris, Aglaophenia, 480

—, Plumularia, 454

—, Thecocarpus, 454, 456

Brucella, 188

— armata, 192

Bythotiara murrayi, 481

caciniformis, Diplocyathus, 158

—, Hydrodendron, 158, 159

—, Ophiodes, 158

—, Ophiodissa, 158

Calamphora, 251

— campanulata, 252, 253

calcarata, Hebella, 182

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 501

calceolifera, Campanularia, 223

—, Eulaomedea, 222, 223

—,-Laomedea, 475

Calicella, 132

— oligista, 131, 132

CALICELLIDAE, 128

caliculata, Campanularia, 208

Calycella oligista, 132

CALYCOPSIDAE, 481

Calycopsis bigelowi, 481

— chuni, 481

Campanularia, 203

— africana, 204,205 ~

— africana, 474

— calceolifera, 223

— caliculata, 208

— compressa, 208

— corrugata, 188

— crenata, 204, 207

— crenata, 206

— delicata, 206, 207

— fastigiata, 137

— fruticosa, 187

— gracilis, 208

— gracillima, 187

— gravieri, 215

— hincksii, 205, 208

— integra, 208, 210

— laminacarpa, 205, 211

— mollis, 212

— morgansi, 212, 216

— mutabilis, 188

— paulensis, 221

— pecten, 212, 214

— roberti, 213, 214

— serpens, 177

— tincta, 204, 474

CAMPANULARIIDAE, 200, 482

campanulata, Calamphora, 252, 253

—, Sertularella, 253

Campanulina turrita, 140

CAMPANULINIDAE, 126

canalifera, Hydractinia, 109, 110

Candelabrum, 45

capensis, Cnidonema, 57

—, Myriothela, 44, 45

—, Sertularella, 282, 284

— delicata, Sertularella, 279

capillare, Eudendrium, 81, 82

—, Eudendrium, 85

carnea, Hydractinia, 113

—, Podocoryne, 481

—, Podocoryne, 113

carneum, Eudendrium, 82, 83

—, Eudendrium, 87

carolinae, Phialucium, 482

Ceratella, 58

— labyrinthica, 63

— minima, 59

— procumbens, 59

— spinosa, 59

ceylonensis, Eirene, 482

chalarocarpa, Aglaophenia, 412

chiquitita, Lovenella, 135, 136

Chromatonema rubrum, 481

chuni, Calycopsis, 481

ciliata, Nemertesia, 382, 383

Cirrholovenia polynema, 482

Cladocarpella, 416

— multiseptata, 418

Cladocarpus, 416

— alatus, 418

— bathyzonatus, 418

— crepidatus, 417, 419

— distomus, 418, 419

— dofleini, 419, 421

— flexilis, 423

— inflatus, 422, 424

— leloupi, 423, 424

— lignosus, 425, 427

— millardae, 424, 426

— multiapertus, 418

— paries, 483, 484

— plumularioides, 418

— sibogae, 418

— sinuosus, 427, 428

— tenuis, 429, 431

— unicornus, 429, 431

— valdiviae, 431, 432

Cladocoryne, 65

— floccosa, 60, 65

CLADOCORYNIDAE, 64

CLADONEMIDAE, 55, 481

Clava, 71

— sp. 71, 73

Clavactinia, 106

— multitentaculata, 105, 106

Clavatella multitentaculata, 54

CLAVIDAE, 69, 481

Clavopsella, 100

— navis, 100, 102

— quadranularia, 100

Clytia, 213

— compressa, 474

— elongata, 221

— gracilis, 217

— gravieri, 215, 216

— hemisphaerica, 217, 219

— hummelincki, 218, 219

— johnstoni, 217

— latitheca, 216, 220

— paradoxa, 219, 220

— paulensis, 221, 222

— raridentata, 474

— serrata, 215

— ulvae, 221

— warreni, 221,222

Cnidonema, 56

502 ANNALS OF THE SOUTH AFRICAN MUSEUM

Cnidonema capensis, 57

— vallenti, 57

Cnidoscyphus, 321

— aequalis, 321

coactum, Dictyocladium, 256, 262

coerulescens, Aequorea, 482

compressa, Campanularia, 208

—, Clytia, 474

conferta, Acryptolaria, 169, 170

—, Aglaophenia, 413

—, Cryptolaria, 169

—, Dicoryne, 101, 102

confertum, Eudendrium, 101

congregata, Sertularella, 283, 284

conica, Aequorea, 482

—, Pandea, 481

conspecta, Gattya, 343, 345

—, Plumularia, 343

constricta, Halopteris, 355

cooperi, Halocordyle, 41

Coppinia arcta, 177

Corhiza, 334

— bellicosa, 334, 336

— mortenseni, 335, 336

— pannosa, 337, 339

— scotiae, 338, 339

— valdiviae, 340, 342

cornicina, Dynamena, 261, 262

cornucopia, Hydrodendron, 160, 161

—, Zygophylax, 160

cornucopiae, Merona, 74, 74

—, Tubiclava, 74

cornuta, Halicornaria, 436

corrugata, Campanularia, 188

—, Hebella, 188

—, Hincksella, 231, 233

Corydendrium, 72

— parasiticum, 72, 73

Corymorpha, 30

Corymorpha sp., 30

CORY MORPHIDAE, 26

Coryne, 51

— eximia, 52

— pusilla, 50, 51

— sp. 471

CORYNIDAE, 48, 481

Cosmetirella davisi, 481

crassipes, Serturella, 281

Crateritheca, 253

— acanthostoma, 253, 255

crenata, Campanularia, 204, 207

—, Campanularia. 206

—, Eucopella, 204

—, Orthopyxis, 204

crepidatus, Cladocarpus, 417, 419

crinoidea, Sertularia, 475

crisioides, Dynamena, 263, 265

cristata, Plumularia, 416

crocea, Parypha,38

—, Tubularia, 38

crosslandi, Dentitheca, 380

—, Plumularia, 380

Cryptolarella, 17°

— abyssicola, 172, 173

Cryptolaria, 174

— abyssicola, 172

— conferta, 169

— pectinata, 174, 176

— rectangataris, 171

cuneata, Sertularella, 476

cupressina, Aglaophenia, 408, 410

Cyanaea bougainvillii, 96

cyathifera, Lictorella, 190

Cyclonia pusilla, 232

cylindrica, Hincksella, 232

—, Sertularella, 232

— pusilla, Hincksella, 232, 233

cylindricum, Synthecium, 232

cymodocea, Antennularia, 384

—, Nemertesia, 384, 387

CYTAEIDAE, 118, 481

Cytaeis, 119

— nassa, 119, 120

Cytaeis tetrastyla, 481

davisi, Cosmetirella, 481

deciduum, Eudendrium, 84, 86

decussata, Antennularia, 384

—, Nemertesia, 384

Dehitella, 58

— atrorubens, 61

delicata, Campanularia, 206, 207

—, Orthopyxis, 206

delicatula, Aglaophenia, 455

—, Plumularia, 455

delicatulum, Halecium, 145, 146

delicatulus, Thecocarpus, 455, 456

dendriformis, Soleniopsis, 72

Dendroclava, 76

Dendrocoryne, 58

dentigerum, Synthecium, 235, 237

Dentitheca, 380

— bidentata, 380, 382

— crosslandi, 380

desmoides, Salacia, 274, 275

—, Sertularia, 274

Desmoscyphus inflatus, 311

Dianaea rotunda, 137

diaphana, Sertularella, 285, 286

—, Thuiaria, 285

dichotoma, Aglaophenia, 413

—, Laomedea, 227

—, Monostaechas, 365

—, Obelia, 227, 228

—, Sertularia, 227

dichotomum, Halec‘um, 147, 149

Dicoryne, 101

— conferta, 101, 102

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

Dicoryne sp. 101

Dictyocladium, 254

— coactum, 256, 262

diegensis, Phialopsis, 482

digitale, Nigellastrum, 257

digitalis, Diphasia, 257, 259

—, Sertularia, 257

Dinotheca, 416

— dofleini, 421

diogenes, Hydractinia, 109, 112

Diphasia, 256

— attenuata, 260

— bipinnata, 260

— digitalis, 257, 259

— heurteli, 258, 259

— nigra, 261

— pinaster, 258

— pinnata, 261

— tetraglochina, 259, 260

Diphasiella, 256

Diplocheilus, 377

— mirabilis, 377

Diplocyathus, 157

— caciniformis, 158

— gracilis, 164

Dipurena halterata, 481

disjuncta, Salacia, 274, 275

dispolians, Hebella, 179, 180

—, Lafoea, 180

distans, Dynamena, 306

—, Sertularia, 306, 308

disticha, Halocordyle, 39, 41

—, Pennaria, 41

distomus, Cladocarpus, 418, 419

dofleini, Cladocarpus, 419, 421

—, Dinotheca, 421

doliolum, Thuiaria, 320

dorhni, Turritopsis, 76

dubia, Obelia, 227

—., Sertularella, 285

— magna, Sertularella, 287, 288

dumortieri, Ectopleura, 481

dumosa, Lafoea, 185

—, Sertularia, 185

Dymella, 271

— articulata, 273

Dynamena, 261

— cornicina, 261, 262

— crisioides, 263, 265

— distans, 306

— gibbosa, 266

— marginata, 311

— obliqua, 266, 267

— operculata, 475

— pluridentata, 253

— pumila, 268

— quadridentata, 265, 266

— tubuliformis, 475

— turbinata, 312

dyssymetrum, Halecium, 149, 150

echinocarpa, Hincksella, 233, 234

—, Sertularia, 234

echinulata, Plumularia, 372

Ectopleura, 32

— bethae, 32, 33

— dumortieri, 481

Egmundella, 132

— amirantensis, 131, 133

Eirene ceylonensis, 482

— hexanemalis, 482

— menoni, 482

— palkensis, 482

EIRENIDAE, 129, 482

elegans, Bicorona, Frontispiece, 49, 50

—, Synthecium, 236, 237

Eleutheria vallentini, 57

ellisi f. mediterranea, Sertularella, 294

ellisti, Thuiaria, 273

elongata, Clytia, 221

—, Sertularia, 313

—, Stereotheca, 313, 315

enigmatica, Zygophylax, 164

Eucalix paradoxus, 220

Eucheilota sp. 482

Eucopella, 203

— crenata, 204

EUDENDRIIDAE, 77

Eudendrium, 79

— angustum, 79, 81

— annulatum, 87

— antarcticum, 80, 81

— capillare, 81, 82

— capillare, 85

— carneum, 82, 83

— carneum, 87

— confertum, 101

— deciduim, 84, 86

— motzkossowskae, 84, 86

— parvum, 82

— ramosum, 85, 92

— ramosum, 97

— ritchiei, 87, 89

— simplex, 84

Eulaomedea, 223

— calceolifera, 222, 223

Euphysora furcata, 481

Eutima levuca, 482

EUTIMIDAE, 129, 482

eximia, Coryne, 52

—, Sarsia, 52, 53

—, Syncoryne, 52

exserta, Halicornaria, 438

exsertum, Gymnangium, 438, 439

falcata, Hydrallmania, 269

—, Plumularia, 269

503

504 ANNALS OF THE SOUTH AFRICAN MUSEUM

falcata, Sertularia, 269

falklandica, Phialella, 482

falsa, Sertularella, 476

fastigiata, Campanularia, 137

—, Stegopoma, 137

faurei, Monostaechas, 362, 364

ferlusi, Gymnangium, 440, 448

—, Halicornaria, 440

filamentosa, Plumularia, 447

filamentosus, Lytocarpus, 447, 448

Filellum, 175

— antarcticum, 176, 177

— antarcticum, 178

— serpens, 177

— serratum, 178, 179

filicaulis, Plumularia, 390, 391

filicula, Aglaophenia, 416

filiformis, Sertularella, 319

—, Sertularia, 319

—, Symplectoscyphus, 319

fisheri v. simplex, Monostaechas, 365

flabellum, Sertularella, 284, 289

—, Thecocladium, 289

flexile, Halecium, 145

flexilis, Cladocarpus, 423

flexuosa, Aglaophenia, 457, 458

—, Plumularia, 398

flexuosus, Thecocarpus, 457

—, Thecocarpus, 458, 461

— flexuosus, Thecocarpus, 458, 459

— plumiferus, Thecocarpus, 460, 462

— solidus, Thecocarpus, 459, 460

— umbellatus, Thecocarpus, 461, 462

floccosa, Cladocoryne, 60, 65

fluminalis, Bimeria, 91, 92

formosa, Aglaophenia, 461

—, Plumularia, 461

formosus, Thecocarpus, 452, 461

frutescens, Aglaophenia, 478

—, Schizotricha, 368

—, Sertularia, 368

fruticosa, Bougainvillia, 97

—, Campanularia, 187

—, Lafoea, 186, 187

—, Spongia, 323

fruticosus, Thyroscyphus, 323, 324

fulva, Bougainvillia, 481

furax, Hebella, 181, 183

furcata, Euphysora, 481

fusca, Aglaophenia, 447

fusiformis, Sertularella, 286, 289

—, Sertularella, 278

—, Sertularia, 289

gaimardi, Aglaophenia, 392

gardineri, Halecium, 162

—, Hydrodendron, 162, 163

—, Leuckartiara, 481

Gattya, 341

— conspecta, 343, 345

— heurteli, 344, 345

— humilis, 345, 346

— multithecata, 348, 350

gaudichaudi, Sertularia, 320

gayi, Sertularella, 305

gayi, Sertularia, 305

gaymardi, Plumularia, 372

gemellipara, Halopteris, 350, 351

geminocarpa, Zygophylax, 194, 195

Gemmaria, 68

geniculata, Laomedea, 229

—, Lictorella, 195

—, Obelia, 228, 229

—, Sertularia, 229

—, Zygophylax, 195, 196

Geryonia octona, 123

giardi, Thecocarpus, 458

— y. solidus, Thecocarpus, 460

gibbosa, Dynamena, 266

gilchristi, Sertularella, 288, 290

glutinosa, Aglaophenia, 352

—, Halopteris, 352, 353

—, Plumularia, 352

goliathus, Sertularella, 291, 293

Gonothyraea, 224

— loveni, 224, 225

gracile, Halecium, 145

gracilicaule, Gymnangium, 441

— gracilicaule, Gymnangium, 442, 443

— lignosum, Gymnangium, 442, 443

gracilicaulis, Halicornaria, 441, 443

—, Lytocarpus, 441

gracilis, Campanularia, 208

—, Clytia, 217

—, Diplocyathus, 164

—, Hydrodendron, 163, 164

—, Laomedea, 217

—, Ophiodes, 164

—, Sarsia, 481

—, Sertularia, 306, 319

gracillima, Campanularia, 187

—, Lafoea, 187

— v. benthophila, Lafoea, 185

Grammaria serpens, 177

grandis, Mitrocomella, 481

Gravelya, 102

gravierae, Lineolaria, 131, 134

gravieri, Campanularia, 215

—, Clytia, 215, 216

Gymnangium, 432

— africanum, 433, 435

— allmanii, 434, 435

— arcuatum, 436, 439

— exsertum, 438, 439

— ferlusi, 440, 448

— gracilicaule, 441

— — gracilicaule, 442, 443

— — lignosum, 442, 443

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

Gymnangium, hians, 435, 444

— longirostre, 445

— montagui, 435, 446

HALECIIDAE, 141

halecina, Sertularia, 150

halecinum, Halecium, 150, 152

halecioides, Lictorella, 190

Halecium, 143

— beanii, 144, 146

— delicatulum, 145, 146

— dichotomum, 147, 149

— dyssymetrum, 149, 150

— flexile, 145

— gardineri, 162

— gracile, 145

— halecinum, 150, 152

— inhacae, 151, 152

— lankesteri, 153, 155

— muricatum, 153, 155

— parvulum, 145

— sessile, 149, 154

— tenellum, 155, 156

Halerella, 118

— siphonis, 118

Halicornaria, 432

— africana, 433

— allmanii, 434

— allmanii var., 446

— arcuata, 436

— cornuta, 436

— exserta, 438

— ferlusi, 440

— gracilicaulis, 441, 443

— hians, 444

— longirostris, 445

— montagui, 446

— plumosa, 434

— segmentata, 447

Halitholus intermedius, 481

Halocharis, 68

Halocordyle, 41

— cooperi, 41

— disticha, 39, 41

— pennaria, 41

HALOCORDYLIDAE, 40

Haloikema lankesteri, 153

HALOPTERINAE, 329

Halopteris, 349

— constricta, 355

— gemellipara, 350, 351

— glutinosa, 352, 353

— polymorpha, 350, 354

— pseudoconstricta, 355, 358

— rostrata, 357, 358

— tuba, 359, 361

— valdiviae, 340

halterata, Dipurena, 481

hartlaubi, Antennularia, 384

Hebella, 178

— calcarata, 182

— corrugata, 188

— dispolians, 179, 180

— furax, 181, 183

— parvula, 179, 182

— scandens, 182, 183

— urceolata, 182

Hebellopsis, 178

— parvula, 182

— scandens, 474

hemisphaerica, Clytia, 217, 219

—, Medusa, 217

hemisphaericum, Phialidium, 217

heterodonta, Aglaophenia, 413

—, Sertularia, 306

Heteroplon, 349

— jaederholmi, 359

— pluma, 352

— valdiviae, 340

Heterotiara anonyma, 481

— minor, 481

heurteli, Diphasia, 258, 259

—, Gattya, 344, 345

—, Paragattya, 344

—, Plumularia, 344

hexanemalis, Eirene, 482

hians, Gymnangium, 435, 444

—, Halicornaria, 444

—, Plumularia, 444

—, Synthecium, 237, 238

Hincksella, 231

— corrugata, 231, 233

— cylindrica, 232

— — pusilla, 232, 233

— echinocarpa, 233, 234

hincksii, Campanularia, 205, 208

holubi, Aglaophenia, 415

humilis, Gattya, 345, 346

hummelincki, Clytia, 218, 219

—, Laomedea, 218

Hybocodon, 32

— unicus, 32, 33

Hydractinia, 108

— altispina, Frontispiece, 108, 110

— canalifera, 109, 110

— carnea, 113

— diogenes, 109, 112

— kaffraria, 111, 112

— marsupialia, 113, 114

— pacifica, 115

— parvispina, 113

— sp., 106, 108

HYDRACTINIIDAE, 104, 481

Hydrallmania, 269

— falcata, 269

Hydrichthys, 122

— boycei, 122, 124

Hydrocorella, 115

505

506 ANNALS OF THE SOUTH AFRICAN MUSEUM

Hydrocorella, africana, Frontispiece, 116, 117

Hydrodendron, 157

— caciniformis, 158, 159

— cornucopia, 160, 161

— gardineri, 162, 163

— gracilis, 163, 164

— sympodiformis, 164, 165

Hypsorophus quadratus, 140

Idia, 269

— pristis, 269

Idiella, 269

Idiellana, 269

— pristis, 267, 269

imperator, Branchiocerianthus, 28, 29

—, Monocaulus, 28

indica, Laodicea, 481

indivisa, Sertularella, 320

indivisus, Symplectoscyphus, 320

inflata, Sertularia, 311

inflatus, Cladocarpus, 422, 424

—, Desmoscyphus, 311

infundibulum, Zygophylax, 197, 199

inhacae, Halecium, 151, 152

inkermanica, Moerisia, 466

—, Ostroumovia, 466, 468, 482

integra, Campanularia, 208, 210

intermedia, Paragattya, 346

intermedius, Halitholus, 481

interrupta, Thuiaria, 263

irregularis, Antennularia, 381

—, Kirchenpaueria, 370, 371

—, Plumularia, 370

jaederholmi, Heteroplon, 359

—, Plumularia, 478

johnstoni, Clytia, 2171

—, Nemertesia, 384

—, Symplectoscyphus, 320

kaffraria, Hydractinia, 111, 112

Kirchenpaueria, 370

—, adhaerens, 376

— irregularis, 370, 371

— mirabilis, 377

— pinnata, 372, 374

— triangulata, 374, 375

KIRCHENPAUERIINAE, 370

KOllikerina multicirrata, 481

labyrinthica, Ceratella, 63

—, Solanderia, 63

laevimarginata, Abietinaria, 246, 248

—, Sertularia, 246

Lafoea, 184

— antarctica, 177

— benthophila, 185, 186

— dispolians, 180

— dumosa, 185

— fruticosa, 186, 187

— gracillima, 187

— gracillima v. benthophila, 185

— magna, 188

— parvula, 182

— scandens, 182

— serrata, 178

LAFOEIDAE, 166

lagenifera, Plumularia, 392, 394

laminacarpa, Campanularia, 205, 211

lankesteri, Halecium, 153, 155

—, Haloikema, 153

Laodicea indica, 481

— undulata, 481

LAODICEIDAE, 129, 481

Laomedea angulata, 223

— bicuspidata, 226

— calceolifera,'475

— dichotoma, 227

— geniculata, 229

— gracilis, 217

— hummelincki, 218

— loveni, 224

— obliqua, 396

— pelagica, 217

— simplex, 270

— striata, 474

Lar, 470

larynx, Tubularia, 35, 36

latecarinata, Aglaophenia, 409, 410

latitheca, Clytia, 216, 220

leiocarpa, Sertularella, 292, 293

—, Sertularia, 292

leloupi, Cladocarpus, 423, 424

Leuckartiara, 123

— annexa, 481

— gardineri, 481

— octona, 123, 124, 481

— vestita, 95

Levinsenia, 313

levuca, Eutima, 482

Lictorella, 188

— antipathes, 190

— cyathifera, 190

— geniculata, 195

— halecioides, 190

lignosa, Aglaophenia, 425

lignosus, Cladocarpus, 425, 427

ligulata, Aglaophenia, 447

—, Sertularia, 307, 310

limbata, Sertularella, 319

linealis, Sertularia, 246, 309

lineata, Sertularella, 289

Lineolaria, 133

Lineolaria gravierae, 131, 134

— sp. 134

loculosa, Sertularia, 312

longa, Sertularella, 301

—, Sertularia, 309, 310

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 507

longirostre, Gymnangium, 445

longirostris, Aglaophenia, 445

—, Halicornaria, 445

Lovenella, 134

— chiquitita, 135, 136

LOVENELLIDAE, 129, 482

loveni, Gonothyraea, 224, 225

—, Laomedea, 224

Lytocarpa, 453

Lytocarpia, 446

Lytocarpus, 446

— filamentosus, 447, 448

— gracilicaulis, 441

— patulus, 447

— philippinus, 449, 452

— phoeniceus, 448, 451

— spectabilis, 451

macgillivrayi, Aglaophenia, 408

macloviana, Bougainvillia, 96, 98, 481

maclovianus, Perigonimus, 96

macrodactyla, Aequorea, 482

macrogona, Sertularella, 316

macrogonus, Symplectoscyphus, 316, 318

Macrorhynchia, 446

— philippina, 449

magna, Lafoea, 188

maplestonei, Amphisbetia, 248, 249

—, Sertularia, 249

—, Thuiaria, 249

marginata, Dynamena, 311

—, Sertularia, 308, 311

marsupialia, Hydractinia, 113, 114

mediterranea, Sertularella, 294

— asymmetrica, Sertularella, 295, 296

— mediterranea, Sertularella, 294, 296

Medusa hemisphaerica, 217

megista, Sertularella, 295, 298

meinertiae, Bougainvillia, 97, 98

menoni, Eirene, 482

Merona, 72

— cornucopiae, 74, 74

millardae, Cladocarpus, 424, 426

minervae, Mitrocoma, 481

minima, Amphisbetia, 248, 250

—, Ceratella, 59

—, Sertularia, 250

—, Solanderia, 59, 60

minor, Heterotiara, 481

—, Monocoryne, 44, 45

mira, Agastra, 208

mirabilis, Diplocheilus, 377

—, Kirchenpaueria, 377

—, Pycnotheca, 377, 378

Mitrocoma minervae, 481

Mitrocomella grandis, 481

MITROCOMIDAE, 129, 481

Modeeria, 137

— rotunda, 137, 139

Moerisia inkermanica, 466

MOERISIIDAE, 464, 482

mollis, Campanularia, 212

Monocaulus imperator, 28

Monocoryne, 43

— minor, 44, 45

Monostaechas, 362

— dichotoma, 365

— faurei, 362, 364

— fisheri v. simplex, 365

— natalensis, 363, 364, 367

— quadridens, 365, 367

Monotheca posidoniae, 396

— yinulosa, 401

montagui, Gymnangium, 435, 446

—, Halicornaria, 446

morgansi, Campanularia, 212, 216

mortenseni, Corhiza, 335, 336

mossambicae, Plumularia, 391, 393

motzkossowskae, Eudendrium, 84, 86

multiapertus, Cladocarpus, 418

multicirrata, KOllikerina, 481

multiseptata, Cladocarpella, 418

multitentaculata, Clavactinia, 105, 106

—, Clavatella, 54

—, Sphaerocoryne, 54

multithecata, Gattya, 348, 350

—, Plumularia, 348

muricata, Sertularia, 153

muricatum, Halecium, 153, 155

murrayi, Bythotiara, 481

muscus, Bougainvillia, 97

mutabilis, Campanularia, 188

—, Proboscidactyla, 482

—, Scandia, 183, 188

Myriothela, 45

— capensis, 44, 45

— tentaculata, 44, 46, 47

MYRIOTHELIDAE, 42

nassa, Cytaeis, 119, 120

—, Podocoryne, 119

natalensis, Antennella, 332

—, Monostaechas, 363, 364, 367

—, Sertularella;-296, 297

navis, Clavopsella, 100, 102

—, Rhizorhagium, 100

Nematocarpus, 416

Nematophorus plumosus,. 480

Nemertesia, 381

— antennina, 381, 382

— ciliata, 382, 383

— cymodocea, 384, 387

— decussata, 384

— johnstoni, 384

— ramosa, 386, 387

Neoturris papua, 481

— pileata, 481

Nigellastrum, 256

508 ANNALS OF THE SOUTH AFRICAN MUSEUM

Nigellastrum digitale, 257

nigra, Diphasia, 261

—, Sertularia, 261

nova, Oswaldella, 376, 378

——, Plumularia, 376

nudum, Rhizogeton, 73, 75

nutricula, Oceania, 76

—, Turritopsis, 73, 76

Obelia, 226

— bicuspidata, 226, 228

— dichotoma, 227, 228

— dubia, 227

— geniculata, 228, 229

— sp., 482

— striata, 215

obliqua, Dynamena, 266, 267

—, Laomedea, 396

—, Plumularia, 396, 397

Oceania armata, 481

— nutricula, 76

octong, Geryonia, 123

—, Leuckartiara, 123, 124, 481

Octotiara russelli, 481

Odontotheca, 247

— bidens, 475

— operculata, 475

oligista, Calicella, 131, 132

Opercularella, 138

— sp., 138, 139

operculata, Amphisbetia, 251, 252

—, Dynamena, 475

—, Odontotheca, 475

—, Sertularia, 251

Ophiodes, 157

— caciniformis, 158

— gracilis, 164

Ophiodissa, 157

— caciniformis, 158

Orthopyxis, 203

— crenata, 204

— delicata, 206

Ostroumovia, 466

— inkermanica, 466, 468, 482

Oswaldaria, 168

Oswaldella, 376

— nova, 376, 378

pacifica, Hydractinia, 115

palkensis, Eirene, 482

Pandea conica, 481

PANDEIDAE, 121, 481

pannosa, Corhiza, 337, 339

papua, Neoturris, 481

paradoxa, Clytia, 219, 220

paradoxus, Eucalix, 220

Paragattya, 341

— heurteli, 344

— intermedia, 346

Paragotoea bathybia, 481

Parascyphus, 270

— simplex, 270, 272

parasitica, Aglaophenia, 461

—, Sertularia, 72

parasiticum, Corydendrium, 72, 73

Parawrightia, 103

— robusta, 103

paries, Cladocarpus, 482, 484

parvispina, Hydractinia, 113

parvula, Aglaophenia, 413

—, Hebella, 179, 182

—, Hebellopsis, 182

—, Lafoea, 182

parvulum, Halecium, 145

parvum, Eudendrium, 82

Parypha, 35

— crocea, 38

Pasya, 261

Pasythea, 261

— quadridentata, 266

patula, Aglaophenia, 447

patulus, Lytocarpus, 447

paulensis, Campanularia, 221

—, Clytia, 221, 222

—, Symplectoscyphus, 317, 318

pecten, Campanularia, 212, 214

pectinata, Acryptolaria, 174

—, Cryptolaria, 174, 176

—, Perisiphonia, 174

—, Thuiaria, 273

pelagica, Laomedea, 217

Pennaria, 41

— australis, 41

— disticha, 41

pennaria, Halocordyle, 41

PENNARIDAE, 40

pennatula, Aglaophenia, 446

—, Plumularia, 446

—, Sertularia, 446

pennycuikae, Plumularia, 398, 403

pensilis, Aequorea, 482

Perigonimus maclovianus, 96

— vestitus f. radicans, 123

Perisiphonia, 174

— pectinata, 174

persocialis, Thuiaria, 273

personalis, Thuiaria, 476

Phialella, 140

— falklandica, 482

— turrita, 139, 140

PHIALELLIDAE, 129, 482

Phialidum, 213

— hemisphaericum, 217

— phosphoricum, 482

— simplex, 482

Phialopsis diegensis, 482

PHIALUCIIDAE, 129, 482

Phialucium carolinae, 482

—— tts

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA 509

Dhilippina, Aglaophenia, 449

—, Macrorhynchia, 449

philippinus, Lytocarpus, 449, 452

phoenicea, Aglaophenia, 451

—, Plumularia, 451

phoeniceus, Lytocarpus, 448, 451

phosphoricum, Phialidium, 482

Phylactotheca, 157

pileata, Neoturris, 481

pinaster, Diphasia, 258

pinnata, Diphasia, 261

—, Kirchenpaueria, 372, 374

—, Plumularia, 372

—, Sertularia, 261, 372

platygaster, Bougainvillia, 481

pluma, Aglaophenia, 411

—, Heteroplon, 352

—, Sertularia, 411

— dichotoma, Aglaophenia, 413, 414

— parvula, Aglaophenia, 413, 414

— pluma, Aglaophenia, 412, 414

plumifera, Aglaophenia, 460

plumosa, Aglaophenia, 447

—, Halicornaria, 434

plumosus, Nematophorus, 480

Plumularia, 388

— africana, 359

— alternata, 352

— antonbruuni, 389, 391

— bidentata, 380

— brevirostris, 454

— conspecta, 343

— cristata, 416

— crosslandi, 380

— delicatula, 455

— echinulata, 372

— falcata, 269

— filamentosa, 447

— filicaulis, 390, 391

— flexuosa, 398

— formosa, 461

— gaymardi, 372

— glutinosa, 352

— heurteli, 344

— hians, 444

— irregularis, 370

— jaederholmi, 478

— lagenifera, 392, 394

— mossambicae, 391, 393

— multithecata, 348

— nova, 376

— obliqua, 396, 397

— pennatula, 446

— pennycuikae, 398, 403

— phoenicea, 451

— pinnata, 372

— polymorpha, 354

— pulchella, 397, 398

— quadridens, 365

— quadridentata, 344

— setacea, 394, 399

— — v. gaimardi, 392

— sp., 398, 479

— spinulosa, 397, 401

— strictocarpa, 402, 403

— tenuis, 404

— triangulata, 375

— tuba, 359

— tubulifera, 416

— unilateralis, 372

— vitiana, 454

— warreni, 403, 404

— wasini, 405, 406

PLUMULARIIDAE, 325

PLUMULARIINAE, 379

plumularioides, Cladocarpus, 418

pluridentata, Dynamena, 253

Podocoryne carnea, 481

— carnea, 113

— nassa, 119

polymorpha, Halopteris, 350, 354

—, Plumularia, 354

polynema, Cirrholovenia, 482

polyzonias, Sertularella, 299

—, Sertularella, 476

—, Sertularia, 299, 476, 477

— falsa, Sertularella, 300, 302

— gigantea, Sertularella, 301, 302

— polyzonias, Sertularella, 300, 302

— xantha, Sertularella, 301, 302

posidoniae, Monotheca, 396

pristis, Idia, 269

—, Idiellana, 267, 269

Proboscidactyla, 470

— mutabilis, 482

PROBOSCIDACTYLIDAE, 467, 482

procumbens, Ceratella, 59

—, Solanderia, 59, 62

pseudoconstricta, Halopteris, 355, 358

pulchella, Plumularia, 397, 398

pulchra, Sertularella, 296, 303

pumila, Dynamena, 268

—, Sertularia, 268

pusilla, Aglaophenia, 416

—, Coryne, 50, 51

—, Cyclonia, 232

Pycnotheca, 377

— mirabilis, 377, 378

quadranularia, Clavopsella, 100

quadratus, Hypsorophus, 140

quadriaurita f. africana, Antenella, 331

quadridens, Monostaechas, 365, 367

—, Plumularia, 365

quadridentata, Dynamena, 265, 266

—, Pasythea, 266

—, Plumularia, 344

—, Sertularia, 266

510 ANNALS OF THE SOUTH AFRICAN MUSEUM

ramosa, Antennularia, 386

—, Bougainvillia, 97, 98

—, Nemertesia, 386, 387

—, Tubularia, 85

ramosum, Eudendrium, 85, 92

—, Eudendrium, 97

—, Synthecium, 236

raridentata, Clytia, 474

—, Thaumantias, 474

rectangularis, Acryptolaria, 171, 173

—, Cryptolaria, 171

regularis, Thyroscyphus, 321

Reticularia, 175

— antarctica, 177

— serpens, 473

— serrata, 178

Rhizogeton, 75

— nudum, 73, 75

Rhizorhagium, 103

— navis, 100

— robustum, 103, 105

rigida, Bimeria, 93, 94

ritchiei, Eudendrium, 87, 89

roberti, Campanularia, 213, 214

robusta, Parawrightia, 103

robustum, Rhizorhagium, 103, 105

rosacea, Sertularia, 260

rostrata, Halopteris, 357, 358

rotunda, Dianaea, 137

— Modeeria, 137, 139

—, Tiaranna, 137

rubra, Agastra, 208

rubrum, Chromatonema, 481

rugosa, Solanderia, 63

russelli, Octotiara, 481

ryniensis, Asyncoryne, 53, 63

Salacia, 217

— articulata, 272, 273

— desmoides, 274, 275

— disjuncta, 274, 275

Sarsia, 52

—eximia, 52, 53

— gracilis, 481

— sp. 481

scandens, Hebella, 182, 183

—, Hebellopsis, 474

—, Lafoea, 182

Scandia, 187

— mutabilis, 183, 188

Scapus, 168

Schizotricha, 368

— frutescens, 368

— simplex, 369, 371

scotiae, Antennopsis, 338

—, Corhiza, 338, 339

secunda, Sertularella, 319

secundaria, Antenella, 332, 333

—, Sertularia, 332

secundus, Symplectoscypnus, 318, 319

segmentata, Halicornaria, 447

serpens, Campanularia, 177

—, Filellum, 177

—, Grammaria, 177

—, Reticularia, 473

serrata, Antennella, 331

—, Clytia, 215

—, Lafoea, 178

—, Reticularia, 178

serratum, Filellum, 178, 179

Sertularella, 276

— africana, 278, 280

— agulhensis, 279, 280

— annulaventricosa, 279, 280

— arborea, 476

— arboriformis, 316

— arbuscula, 280, 281

— campanulata, 253

— capensis, 282, 284

— capensis delicata, 279

— congregata, 283, 284

— crassipes, 281

— cuneata, 476

— cylindrica, 232

— diaphana, 285, 286

— dubia, 285

— dubia magna, 287, 288

— ellisi f. mediterranea, 294

— falsa, 476

— filiformis, 319

— flabellum, 284, 289

— fusiformis, 286, 289

— fusiformis, 278

— gayi, 305

— gilchristi, 288, 290

— goliathus, 291, 293

— indivisa, 320

— leiocarpa, 292, 293

— limbata, 319

— lineata, 289

— longa, 301

— macrogona, 316

— mediterranea, 294

— — asymmetrica, 295, 296

— — mediterranea, 294, 296

— megista, 295, 298

— natalensis, 296, 297

— polyzonias, 299

— polyzonias, 476

— — falsa, 300, 302

— — gigantea, 301, 302

— — polyzonias, 300, 302

— — xantha, 301, 302

— pulchra, 296, 303

— secunda, 319

— sp. 476

— striata, 298, 304

— tenella, 279

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA ed

Sertularella tumida, 476

— undulata, 279

— unilateralis, 320

— xantha, 301

sertularellae, Tubularia, 35

Sertularia, 305

— abietina, 247

— acanthostoma, 253

— acuta, 312

— antennina, 381

— antipathes, 190

— aperta, 251

— arbuscula, 281

— argentea, 313

— articulata, 273

— bidens, 249

— crinoidea, 475

— desmoides, 274

— dichotoma, 227

— digitalis, 257

— distans, 306, 308

— dumosa, 185

— echinocarpa, 234

— elongata, 313

— falcata, 269

— filiformis, 319

— frutescens, 368

— fusiformis, 289

— gaudichaudi, 320

— gayi, 305

— geniculata, 229

— gracilis, 306, 319

— halecina, 150

— heterodonta, 306

— inflata, 311

— laevimarginata, 246

— leiocarpa, 292

— ligulata, 307, 310

— linealis, 246, 309

— loculosa, 312

— longa, 309, 310

— maplestonei, 249

— marginata, 308, 311

— minima, 250

— muricata, 153

— nigra, 261

— operculata, 251

— parasitica, 72

— pinnata, 261, 372

— pluma, 411

— polyzonias, 299, 476, 477

— pumila, 268

— quadridentata, 266

— rosacea, 260

— secundaria, 332

— setacea, 399

— turbinata, 310, 312

— unilateralis, 320

SERTULARIIDAE, 239

sessile, Halecium, 149, 154

setacea, Plumularia, 394, 399

—, Sertularia, 399

— v. gaimardi, Plumularia, 392

sibogae, Cladocarpus, 418

—, Zygophylax, 198, 199

simplex, Eudendrium, 84

—, Laomedea, 270

—, Parascyphus, 270, 272

—, Phialidium, 482

—, Schizotricha, 369, 371

—, Thyroscyphus, 270

sinuosus, Cladocarpus, 427, 428

siphonis, Halerella, 118

—, Stylactella, 118

—, Stylactis, 118

Solanderia, 58

— atrorubens, 61

— labyrinthica, 63

— minima, 59, 60

— procumbens, 59, 62

— rugosa, 63

SOLANDERIIDAE, 58

Soleniopsis, 72

— dendriformis, 72

solitaria, Tubularia, 40

solitarius, Zyzzyzus, 39, 40

spectabilis, Lytocarpus, 451

Sphaerocoryne, 54

— bedoti, 53, 54

— multitentaculata, 54

spinosa, Ceratella, 59

spinulosa, Monotheca, 401

—, Plumularia, 397, 401

Spongia fruticosa, 323

Spongiocladium, 58

Stauridiosarsia, 52

Staurocladia, 56

— vallentini, 57, 67, 481

Staurocoryne, 51

Steenstrupia, 30

Stegopoma fastigiata, 137

Stereotheca, 313

— acanthostoma, 475

— elongata, 313, 315

striata, Loamedea, 474

—, Obelia, 215

—, Sertularella, 298, 304

strictocarpa, Plumularia, 402, 403

Stylactella siphonis, 118

Stylactis, 118

— siphonis, 118

subventricosum, Synthecium, 236

Symplectanea, 43

Symplectoscyphus, 314

— arboriformis, 315, 316

— filiformis, 319

— indivisus, 320

— johnstoni, 320

Sy ANNALS OF THE SOUTH AFRICAN MUSEUM

Symplectoscyphus macrogonus, 316, 318

— paulensis, 317, 318

— secundus, 318, 319

— unilateralis, 320

sympodiformis, Hydrodendron, 164, 165

Syncoryna, 51

Syncoryne eximia, 52

SYNTHECIIDAE, 230

Synthecium, 235

— cylindricum, 232

— dentigerum, 235, 237

— elegans, 236, 237

— hians, 237, 238

— ramosum, 236

— subventricosum, 236

tenella, Sertularella, 279

tenellum, Halecium, 155, 156

tentaculata, Myriothela, 44, 46, 47

tenuis, Cladocarpus, 429, 431

—, Plumularia, 404

tetraglochina, Diphasia, 259, 260

tetrastyla, Cytaeis, 481

Thaumantias raridentata, 474

Thecocarpus, 453 ;

— brevirostris, 454, 456

— delicatulus, 455, 456

— flexuosus, 457

— — flexuosus, 458, 459

— — plumiferus, 460, 462

— — solidus, 459, 460

— — umbellatus, 461, 462

— formosus, 452, 461

— giardi, 458, 460

Thecocaulus, 349

— tuba, 478

— valdiviae, 340

Thecocladium, 276

— flabellum, 289

Thoa beanii, 144

Thuiaria, 430

— articulata, 273

— diaphana, 285

— doliolum, 320

— ellisii, 273

— interrupta, 263

— maplestonei, 249

— pectinata, 273

— persocialis, 273

— personalis, 476

— tubuliformis, 263

Thyroscyphus, 321

— aequalis, 321, 322

— fruticosus, 323, 324

— regularis, 321

— simplex, 270

Tiaranna, 137

— rotunda, 137

tincta, Campanularia, 204

triangulata, Kirchenpaueria, 374, 375

—, Plumularia, 375

Tridentata acuta, 312

tuba, Halopteris, 359, 361

—, Plumularia, 359

—, Thecocaulus, 478

Tubiclava cornucopiae, 74

Tubularia, 35

— betheris, 32

— crocea, 38

— larynx, 35, 36

— ramosa, 85

— sertularellae, 35

— solitaria, 40

— warreni, Frontispiece, 35, 36

TUBULARIIDAE, 30, 481

tubulifera, Aglaophenia, 416

—, Plumularia, 416

tubuliformis, Dynamena, 475

—, Thuiaria, 263

tumida, Sertularella, 476

turbinata, Dynamena, 312

—, Sertularia, 310, 312

turrita, Campanulina, 140

—, Phialella, 139, 140

Turritopsis, 76

— dorhni, 76

— nutricula, 73, 76

ulvae, Clytia, 221

undulata, Laodicea, 481

—, Sertularella, 279

unicornus, Cladocarpus, 429, 431

unicus, Amphicodon, 32

—, Hybocodon, 32, 33

unilateralis, Plumularia, 372

—, Sertularella, 320

—, Sertularia, 320

—, Symplectoscyphus, 320

urceolata, Hebella, 182

vagans, Zygocanna, 482

valdiviae, Cladocarpus, 431, 432

—, Corhiza, 340, 342

—, Halopteris, 340

—, Heteroplon, 340

—, Thecocaulus, 340

vallentini, Cnidonema, 57

—, Eleutheria, 57

—, Staurocladia, 57, 67, 481

van Benedeni, Bougainvillia, 97

vestita, Bimeria, 94, 95

—, Leuckartiara, 95

vestitus f. radicans, Perigonimus, 123

vitiana, Aglaophenia, 454

—, Plumularia, 454

warreni, Clytia, 221, 222

—, Plumularia, 403, 404

—, Tubularia, Frontispiece, 35, 36

MONOGRAPH ON THE HYDROIDA OF SOUTHERN AFRICA

wasini, Plumularia, 405, 406 — africana, 189, 191

Willia, 470 — antipathes, 190, 191

Wrightia, 103 — armata, 192, 194

— biarmata, 193, 194

. — cornucopia, 160

xantha, Sertularella, 301 — enigmatica, 164

— geminocarpa, 194, 195

Zanclea, 68 — geniculata, 195, 196

— sp. 67, 68 ’ — infundibulum, 197, 199

ZANCLEIDAE, 66 — sibogae, 198, 199

Zygocanna vagans, 482 Zyzzyzus, 38

Zygophylax, 188 — solitarius, 39, 40

513

6. SYSTEMATIC papers must conform with the International code of zoological nomenclature

(particularly Articles 22 and 51).

Names of new taxa, combinations, synonyms, etc., when used for the first time, must be

followed by the appropriate Latin (not English) abbreviation, e.g. gen. n., sp. n., comb. n.,

syn. n., etc.

An author’s name when cited must follow the name of the taxon without intervening

punctuation and not be abbreviated; if the year is added, a comma must separate author’s

name and year. The author’s name (and date, if cited) must be placed in parentheses if a

species or subspecies is transferred from its original genus. The name of a subsequent user of

a scientific name must be separated from the scientific name by a colon.

Synonymy ‘arrangement should be according to chronology of names, i.e. all published

scientific names by which the species previously has been designated are listed in chronological

order, with all references to that name following in chronological order, e.g.:

Family Nuculanidae

Nuculana (Lembulus) bicuspidata (Gould, 1845)

Figs 14-15A

Nucula (Leda) bicuspidata Gould, 1845: 37.

Leda plicifera A. Adams, 1856: 50.

Laeda bicuspidata Hanley, 1859: 118, pl. 228 (fig. 73). Sowerby, 1871: pl. 2 (figs 8a—b).

Nucula largillierti Philippi, 1861: 87

Leda bicuspidata: Nicklés, 1950: 163, fig. 301; 1955: 110. Barnard, 1964: 234, figs 8-9,

Note punctuation in the above example:

comma separates author’s name and year

semicolon separates more than one reference by the same author

full stop separates references by different authors

figures of plates are enclosed in parentheses to distinguish them from text-figures

dash, not comma, separates consecutive numbers

Synonymy arrangement according to chronology of bibliographic references, whereby

the year is placed in front of each entry, and the synonym repeated in full for each entry, is

not acceptable.

In describing new species, one specimen must be designated as the holotype; other speci-

mens mentioned in the original description are to be designated paratypes; additional material

not regarded as paratypes should be listed separately. The complete data (registration number,

depository, description of specimen, locality, collector, date) of the holotype and paratypes

must be recorded, e.g.:

Holotype

SAM-A13535 in the South African Museum, Cape Town. Adult female from mid-tide region, King’s Beach,

Port Elizabeth (33.51S, 25.39E), collected by A. Smith, 15 January 1973.

Note standard form of writing South African Museum registration numbers and of date.

7. SPECIAL HOUSE RULES

Capital initial letters

(a) The Figures, Maps and Tables of the paper when referred to in the text

e.g. ‘... the Figure depicting C. namacolus...’

*... in C. namacolus (Fig. 10)...’

(b) The prefixes of prefixed surnames in all languages, when used in the text, if not preceded

by initials or full names

e.g. Du Toit but A. L. du Toit

Von Huene but F. von Huene

e.g. Therocephalia, but therocephalian

Punctuation should be loose, omitting all not strictly necessary

Reference to the author should be expressed in the third person

Roman numerals should be converted to arabic, except when forming part of the title of a

book or article, such as

‘Revision of the Crustacea. Part VIII. The Amphipoda.’

Specific name must not stand alone, but be preceded by the generic name or its abbreviation

to initial capital letter, provided the same generic name is used consecutively.

N. A. H. MILLARD

MONOGRAPH ON THE HYDROIDA

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o a faa eee Sy oO

é 2 < ‘2G : :

ca = ig a a