European Journal of Taxonomy 77: 1-18

http://dx.doi.org/lQ.5852/ejt.2Q14.77

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2Q14 • Nzigidahera B. & Joeque R.

Research article

urn:lsid:zoobank.org:pub:855E32F7-E680-4BC6-A8F4-630ED7FAD5C3

On the Afrotropical genus Holmelgonia (Araneae, Linyphiidae), with

the description of three new species from the Albertine Rift

Benoit NZIGIDAHERA'"^ & Rudy JOCQUE

^ Institut National pour EEnvironnement et la Conservation de la Nature (INECN), B.R 2757

Bujumbura, Burundi. E-mail: [email protected]

^ Corresponding author: Royal Museum for Central Afriea (MRAC), B-3Q8Q Tervuren, Belgium.

E-mail: [email protected]

^ um: Isid: zoobank, org: author: 3112C6AF -BB9B-4CF7-BQA6-A7Q9D2473A25

^ um:lsid:zoobank.org:author:CF15Q16C-8CD1-4C9D-9Q21-44CA7DC7A5D5

Abstract. Three new speeies of Holmelgonia were found in the mountain forest of Kibira National Park

in Burundi: H. afromontana sp. nov. (c??), H. bosnasutus sp. nov. (c??) and//, disconveniens sp. nov.

((J). A key to the males in the genus, now eontaining 17 speeies, is provided.

Key words. Afromontane forest, Burundi, Kibira National Park, identifieation key, speeies swarm.

Nzigidahera B. & Joeque R. 2Q14. On the Afrotropical genus Holmelgonia (Araneae, Linyphiidae), with the

description of three new species from the Altertine Rift. European Journal of Taxonomy 77: 1-18. http://dx.doi.

org/lQ.5852/eit.2Q14.77

Introduction

Einyphidae have been popular among students of Afrotropieal spiders and figure among the better known

families of the eontinent, as far as the speeies living in the leaf litter layer is eoneemed. The interest in

the family doubtlessly originated in the expertise several taxonomists had aequired in Europe, where

the family Einyphiidae is by far the most speeiose. Mainly Bosmans, Denis, Holm, Joeque, Miller,

Russell-Smith and Seharff all eontributed to a great extent to the knowledge of the family thanks to the

experienee they had obtained by studying the European linyphiids. By the end of the last eentury, their

extensive studies had yielded enough information about the family to result in an interaetive key to the

genera (Seyfulina & Joeque 2QQ7) and to allow generalisations about the distribution of the family, sueh

as for instanee the abundanee of montane speeies (Seharff 199Q, 1992, 1993) as eompared to the paueity

of the family in Afriean lowland habitats and the small size of Afrotropieal litter inhabiting linyphiids

(Joeque et al. 2Q13).

More reeently, the fauna of the eanopy yielded a high number of unknown linyphiid taxa (see Seyfulina

& Joeque 2QQ9). Although the interest in Afrotropieal linyphiids has apparently dwindled, the reeent

study by Friek & Seharff (2Q13) proves that the interest in Afrotropieal linyphiids still slumbers.

The present study aims to stimulate renewed interest in Afriean linyphiids and is the first of a series of

papers on linyphiids from the southern part of the Albertine Rift, a mountain range with a partieularly

European Journal of Taxonomy 77 : 1-18 ( 2014 )

diverse fauna (Nzigidahera & Joeque 2009; Joeque et al. 2013). It provides an overview of the endemie

Alfotropieal genus Holmelgonia Joeque & Seharff, 2007. The genus, originally deseribed by Holm

(1962) as Elgonella, reeeived the replaeement name Elgonia Platniek (1986), but eventually beeame

Holmelgonia sinee Elgonia also turned out to be a homonym (Joeque & Seharff 2007).

The genus Holmelgonia eontains 14 speeies (Platniek 2013) and has a wide distribution (see Fig. 1)

ranging from Cote d’Ivoire in the west to Kenya and Mozambique in the east. Although most speeies

live at high altitude and have small endemie ranges (Joeque & Seharff 1986; Seharff 1993), some of

them (e.g., H. holmi Miller, 1970; H. brachystegiae Joeque, 1981) have a wide distribution at mid¬

altitude.

Here we deseribe three new speeies from Burundi and provide a key to all the speeies for whieh males

have been deseribed.

The eolleetions from whieh the type material of the new speeies originates are the result of an extensive

sampling eampaign earried out by the first author in proteeted areas of Burundi during three periods in

2003, 2005 and 2008. They eovered altitudinal gradients between 1970 m and 2650 m above sea level

(asl). The diseovery emphasizes the biodiversity of the Albertine Rift spider fauna with high numbers of

speeies in many spider groups (Nzigidahera & Joeque 2009).

Fig. 1. Presently known distribution of Holmelgonia Joeque & Seharff, 2007. Large arrow indieates

Kibira National Park, type loeality of the speeies deseribed in this paper.

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

Material and methods

The speeimens were eolleeted by the first author in the afromontane forest of Kibira. Primary types are

deposited in the Musee Royal de TAfrique Centrale, Tervuren, Belgium (MRAC), whereas paratypes

are divided among MRAC and the Institut National pour TEnvironnement et la Conservation de la

Nature, Bujumbura, Burundi (INECN). Speeimens were observed, drawn and measured with a WILD

M 10 stereo mieroseope. Details of the epigyne and male palps were observed with a Zeiss Stemi 2000

strereo mieroseope.

Epigynes were detaehed from the abdomen, eleared with methyl salieylate and temporarily mounted in a

mixture of methyl salieylate and eedukol for examination. The same method was used to observe details

of the male palp. These struetures were photographed with a Leiea MZ16 stereo mieroseope and subjeet

to automontage with the Syneroseopy software. All measurements are in mm. As with the illustrations,

they were taken from the holotype and paratypes unless stated otherwise. Coordinates are in deeimal

format.

Abbreviations

ALE =

anterior lateral eyes

AME =

anterior median eyes

anterior width

dorsal

dorsolateral

diameter of tibia

embolie division

femur

length

median apophysis

Figs 2-3. Holmelgonia disconveniens sp. nov. (cJ, MRAC 227149). 2. SEM mierographs of ehelieerae,

lateral view, showing absenee of stridulating ridges. 3. Detail of previous. Seale bars =100 pm.

European Journal of Taxonomy 77 : 1-18 ( 2014 )

metatarsus

patella

prolateral

PEE =

posterior lateral eyes

PME =

posterior median eyes

retrolateral

tarsus

tibia

position of triehobothrium on metatarsus expressed as ratio of distanee to base and

length of segment

ventral

Taxonomy

Class Arachnida Cuvier, 1812

Order Araneae Clerek, 1757

Family Linyphiidae Blaekwall, 1859

Subfamily Erigoninae Emerton, 1882

Holmelgonia Joeque & Seharfif, 2007

Type species

Elgonella nemoralis Holm, 1962

Diagnosis

The generie definition is wide, as the original diagnosis by Holm (1962) had to be enlarged by Joeque &

Seharff (1986) to aeeommodate the speeies from Tanzanian mountain areas. The genus is eharaeterized

by the absenee of ehelieeral stridulating ridges (Figs 2-3); the presenee of a double ventral row of setae

on the femora; the long tibial spines, two to three times as long as the diameter of the segment; tibia 1-lV

with 2, 2, 1 and 1 spine, respeetively; TMl between 0.32 and 0.7; males laek a eephalie lobe; the palpal

tibia dorsally produeed into a dorsal proeess (Figs 4-5, 7).

Key to the species of Holmelgonia (males only)

1. Dorsal tibial apophysis apieally without teeth, smoothly rounded and with many long hairs (A)

. H. afromontana sp. nov. (Burundi)

- Dorsal tibial apophysis apieally with teeth, sometimes with many hairs .2

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

2. Dorsal tibial apophysis apically with two teeth (Cl), eaeh provided with hair (C2) but without

teeth or undulation on the margins .3

- Dorsal tibial apophysis with teeth or undulation on the retrolateral margin (B2, dorsal view)

or on distal part (B3, retrolateral view), apart from apieal teeth (Bl, dorsal view) .7

3. Dorsal tibial apophysis originating at the proximal base of tibia, straight, pointing upward (Dl);

retrolateral tibial apophysis absent (D2) .

. H. brachystegiae (Joeque, 1981) (Burundi, Malawi, Tanzania)

- Dorsal tibial apophysis obliquely oriented (El); retrolateral tibial apophysis eonieal (E2), toothed

(F) or rounded at the tip (G).4

4. Retrolateral tibial apophysis eonieal (E2) or rounded at the tip (G) .5

- Retrolateral tibial apophysis with teeth (F).6

5. Distal arm of paraeymbium with indented posterior proeess (H); embolus semieireular or siekle-

shaped (I) . H. falciformis (Seharff, 1990) (Uzungwa Mts, Tanzania)

- Distal arm of paraeymbium with simple posterior proeess (J); embolus with sharp bend (K) ...

. H. annemetteae (Seharff, 1990) (Uzungwa Mts, Tanzania)

6. Retrolateral tibial apophysis with blaekened teeth (F) on the transerverse ridge under the dorsal

tibial apophysis. H. annulata (Joeque & Seharff, 1986) (Uluguru Mts, Tanzania)

- Retrolateral tibial apophysis with a single tooth on the lateral ridge (E) .

. H. basalis (Joeque & Seharff, 1986) (Usambara Mts, Tanzania)

7. Dorsal tibial apophysis with one tooth at the tip (M2); retrolateral tibial apophysis pointed at

the tip (Ml) . H. disconveniens sp. nov. (Burundi)

- Dorsal tibial apophysis with two teeth at the tip (Bl, B2, Cl) .8

8. Dorsal tibial apophysis with a row of five teeth on the margin (N) .

. H. producta (Bosmans, 1988) (Cameroon)

- Dorsal tibial apophysis with undulation on the prolateral margin (B2) or many small teeth near

apieal part (B3) .9

European Journal of Taxonomy 77 : 1-18 ( 2014 )

9. Dorsal tibial apophysis with undulation on the prolateral margin (B2) .10

- Dorsal tibial apophysis with many small teeth on the apieal part (B3) .12

10. Dorsal tibial apophysis with a large prolateral lobe (O) .

. H. holmi (Miller, 1970) (Congo, Cameroon)

- Dorsal tibial apophysis with small prolateral lobes or teeth on the margin (B2) .11

11. Distal arm of paraeymbium rounded at tip (PI), proximal arm broad at base (P2) .

. H. bosnasutus sp. nov. (Burundi)

- Distal arm of paraeymbium hooked at the tip (Ql), proximal arm narrow at base (Q2).

. H. nemoralis (Holm, 1962) (Kenya)

12. Embolie division ventrally with numerous small teeth (Rl); frontal embolar apophysis very long

(R2), eentral embolar apophysis very short (R3) and adjaeent to embolus (R4).

. H. perturbatrix (Joeque & Seharfif, 1986) (Usambara Mts, Tanzania)

- Embolie division ventrally without teeth; frontal embolar apophysis very long and twisted (SI),

eentral embolar apophysis on lateral side of division (S2) delimiting a eoneavity provided with

numerous small warts (S3). H. projecta (Joeque & Seharff, 1986) (Uluguru Mts, Tanzania)

Holmelgonia afromontana sp. nov.

um:lsid:zoobank.org:aet:F482911E-4987-4F7E-BC74-D4101DE9EE29

Figs 4-5, 8, 11-16, 26-29, 39

Diagnosis

The male is eharaeterized by the dorsal tibial apophysis, whieh is smoothly rounded at the extremity

and has a ventral eoneavity provided with a short, sharp, tooth-shaped exereseenee inside. Proximal

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

and distal arms of the paraeymbium with short setae, distal arm strongly selerotized and eurved at the

tip. The female is reeognized by details of the epigyne of whieh the eentral depression and the kidney¬

shaped spermatheeae are the most eharaeteristie.

Etymology

The speeifie name 'afromontana ’refers to the high altitude habitat in whieh the speeies was eolleeted.

Figs 4-10. SEM mierographs. — 4-5, 8. Holmelgonia afromontana sp. nov. {S, MRAC 227153).

4. Palp, retrolateral view. 5. As previous, ventral view. 8. Embolie division, frontal view. —

6, 9. Holmelgonia bosnasutus sp. nov. {S, MRAC 227145). 6. Palp, retrolateral view.

9. Embolie division, ventral view. — 7, 10. Holmelgonia disconveniens sp. nov. (3, MRAC 241448).

7. Palp, retrolateral view. 10. Embolie division, frontal view. Seale bars 4-7 = 100 pm; 9-10 = 50 pm;

8 = 20 pm. E: embolus.

European Journal of Taxonomy 77 : 1-18 ( 2014 )

Material examined

Holotype

BURUNDI: S, Parc National de la Kibira, Rwegura, Mt. Musumba, 2.86445° S, 29.49640° E, site 5,

forest with Carapa grandiflora ?indiPolyscias fulva, 25 Jun. 2008, 2252 m, pitfalls, B. Nzigidahera eoll.

(MRAC 227154).

Paratypes

BURUNDI: All from Pare National de la Kibira, Rwegura, Mt Musumba, pitfalls, B. Nzigidahera eoll.

- 1 $, together with holotype (MRAC 227154). - 2.86435° S, 29.49546° E, site 6, forest with Carapa

grandiflora Polysciasfulva, 2150 m: 1 (J, 2 5 ?, 10 Mar. 2008 (MRAC 227159); 1 S, 25 Aug. 2008

(INECN); 3 (?(?, 10 Nov. 2008 (E4ECN); 1 S, 10 Nov. 2008 (INECN); 2 fS, 25 Jul. 2008 (INECN); 1

S, 1 juv., 10 Jul. 2008 (MRAC 227157); 1 ?, 25 Mar. 2008 (MRAC 227161). -2.86445° S, 29.49640°

E, site 5, forest with Carapa grandiflora and Polyscias fulva, 2252 m: 1 (5^, 10 Apr. 2008 (MRAC

227148); 1 S, 10 May 2008 (MRAC 227156); !(?,!?, 25 Aug. 2008 (MRAC 227151); 1 S, 10 Aug.

2008 (INECN); 1 (?, 10 Aug. 2008 (MRAC 227158); 2 10 Jun. 2008 (INECN); 5 SS, 25 Feb. 2008

(INECN); 1 S, 25 Nov. 2008 (INECN); !(?,!?, 10 Feb. 2008 (INECN); 2 SS, 1 juv., 25 Sep. 2008

(INECN). - 2.86455° S, 29.50427° E, site 4, forest with Macaranga neomildbraediana and Polyscias

fulva, 2352 m: 1 ?, 25 Jun. 2008 (MRAC 227152); 3 SS, 10 Feb. 2008 (MRAC 227153); If, 25 Feb.

2008 (INECN); 1 f, 10 Get. 2008 (INECN); 1 f, 1 juv., 10 Sep. 2008 (INECN); If, 25 Feb. 2008

(INECN). - 2.87149° S, 29.49641° E, site 3, 2444 m: 2 ff, 26 Jan. 2008 (INECN). - 2.87696°S,

29.49709° E, site 1, 2650 m: 3 ? ?, 25 Get. 2008 (INECN).

Other material

BURUNDI: Pare National de la Kibira, Foret de Rwegura, pitfalls, B. Nzigidahera eoll., 2.90249°E,

29.51345°S, forest with Macaranga neomildbreadiana dXY&Xymalos monospora, 2223 m, 1 f, 23 Nov.

2003 (INECN).

Description

Male (holotype. Figs 4-5, 8, 11-13, 26-27, 29)

Measurements. Total length 1.70, earapaee 0.70 long, 0.60 wide.

CEPEL4EOTHORAX. Carapaee medium brown, with blaek striae radiating from foveal area. Chelieerae

yellow, mottled with grey. Retromargin of ehelieerae with 5 teeth; promargin with 4 small teeth. Clypeus

2 times AEE, grey. Sternum dark brown mottled with blaek, shield-shaped, 0.48 long and 0.44 wide.

Eyes. Geular area blaek. Posterior eye row strongly proeurved, anterior eye row reeurved; AME 0.04,

AEE 0.08, PME 0.08, PEE 0.08.

Eegs. Pale yellow; tibia 1 with two spines. Femora without dorsal spines, with ventral spines in two

rows. Metatarsi without dorsal spines.

Eeg measurements

Legs

Total

0.72

0.22

0.66

0.60

0.52

2.72

0.70

0.22

0.62

0.54

0.50

2.58

111

0.62

0.20

0.56

0.54

0.40

2.32

0.82

0.20

0.80

0.72

0.44

2.98

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

Figs 11-25. — 11-16. Holmelgonia afromontana sp. nov. (3 holotype, $ paratype 227154).

11. Habitus, 3, dorsal view. 12. Habitus, 3, ventral view. 13. Habitus, 3, lateral view.

14. Habitus, $, dorsal view. 15. Habitus, $, ventral view. 16. Habitus, $, lateral view. —

17-22. Holmelgonia bosnasutus sp. nov. {S holotype, female paratype 227507). 17. Habitus,

S, dorsal view. 18. Habitus, S, ventral view. 19. Habitus, S, lateral view. 20. Habitus, $,

dorsal view. 21. Habitus, $, ventral view. 22. Habitus, $, lateral view. — 23-25. Holmelgonia

disconveniens sp. nov. (S' holotype). 23. Habitus, dorsal view. 24. Habitus, ventral view.

25. Habitus, lateral view. Seale bars = 0.5 mm.

European Journal of Taxonomy 77 : 1-18 ( 2014 )

Leg chaetotaxy

Legs TM Tibial spines

Proximal Distal

Position

Eength/DT

Position

Eength/DT

0.40

0.16

1.80

0.50

1.60

0.20

0.14

2.20

0.42

1.40

111

0.20

0.12

3.25

0.30

0.12

3.50

Abdomen. Oval, pale grey, dorsally with pale spots and four faint horizontal ehevrons beeoming smaller

towards the rear end. Spinnerets pale yellow, eonieal.

Paep (Figs 4-5, 8, 26-27, 29). Dorsal tibial apophysis ventrally eoneave, with tooth-shaped exereseenee

inside eoneavity; dorsally with smoothly rounded tip. Paraeymbium: proximal arm tapered, with row

of short hairs; distal arm with two lobes at extremity, eaudal one with some hairs. Prolateral part of

subtegulum with oblique grooves. Embolie division (Fig. 29) fairly simple; embolus long, frontal

appendage short, truneated, margin with many tiny teeth; dorsal appendage short, rounded.

Female (paratype, MRAC 227154, Figs 14-16, 28, 39)

Habitus similar to male.

Figs 26-29. Holmelgonia afromontana sp. nov. {S holotype, $ paratype 227154). 26. Palp, S, retrolateral

view. 27. Palp, S, dorsal view. 28. Epigyne, ventral view. 29. Embolie division of S palp, ventrolateral

view. Seale bars = 0.1 mm.

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

Measurements. Total length 1.64. Carapaee 0.70 long, 0.60 wide.

Cephaeothorax. Clypeus 1.66 times ALE. Sternum 0.48 long, 0.46 wide.

Eyes. AME 0.04, AEE 0.08, PME 0.08, PEE 0.08.

Eeg measurements

Legs

Total

0.70

0.22

0.58

0.52

0.40

2.42

0.74

0.22

0.50

0.44

2.40

III

0.64

0.20

0.44

0.36

2.08

0.80

0.20

0.66

0.46

2.78

Eeg chaetotaxy

Legs

Tibial

spines

Proximal

Distal

Position

Eength/DT

Position

Eength/DT

0.33

0.22

2.00

0.42

1.80

0.36

0.10

2.00

0.38

2.00

III

0.40

0.12

3.25

0.54

0.16

4.00

Epigyne (Fig. 30). Fairly large ventral plate broadly indented in front, posterior margin slightly proeurved.

Copulatory duets originate from eentre near posterior margin, entering spermatheeae near lateral margin;

spermatheeae large, kidney-shaped, with transverse long axis.

Variation

Carapaee eolour may vary from medium brown to yellowish grey.

Distribution

Known only from the type loeality (Fig. 1).

Holmelgonia bosnasutus sp. nov.

um:lsid:zoobank.org:aet:098B9E4B-00C0-437E-A36E-EEE46A2D9826

Figs 6, 9, 17-22, 30-34, 40

Diagnosis

The male is eharaeterized by the sharply pointed dorsal tibial apophysis with undulated margin, eaeh

undulation provided with a hair, eombined with the broad prolateral apophysis, the broad proximal arm

and smoothly rounded tip of the distal arm of the paraeymbium. Females are reeognized by the shape of

the epigyne, provided with two holes elearly visible and opening in the posterior margin.

Etymology

The speeifie name 'bosnasutus ’refers to the shape of the epigyne whieh is reminseent of a eow’s nose.

European Journal of Taxonomy 77 : 1-18 ( 2014 )

Material examined

Holotype

BURUNDI: S, Parc National de laKibira, Mt. Musumba, Rwegura, 2°52’ S, 29°30’ E, 28 Dec. 2004, site

2, forest with Hagenia abyssinica, B. Nzigidahera eoll. (MRAC 227508).

Paratypes

BURUNDI: All from Pare National de la Kibira, foret de Rwegura, pitfalls, B. Nzigidahera eoll. -

2.89565° S, 29.50345° E, site 2, forest with Polyscias fulva and Macaranga neomildbraediana, 2120

m: 1 3, 29 Jun. 2005 (INECN); 1 3, 28 Dee. 2004 (MRAC 227567). - 2.88562°S, 29.50221°E, site 3,

forest with Polyscias fulva md Hagenia abyssinica, 2160 m: 1 27 May 2005 (MRAC 227507); 1 3,

15 Mar. 2005 (INECN). -2.89435° S, 29.50078°E, site 4, 2400 m: 2 33 , 28 Feb. 2005 (INECN); 1 3 ,

28 Dee. 2004 (INECN^

Other material

BURUNDI: Pare National de la Kibira, Rwegura, Mt Musumba, B. Nzigidahera eoll., 2.86435°S,

29.49540°E, site 7, tea plantation, 2100 m: 1 3 , 25 Aug. 2008 (MRAC 227146); 1 3 , 10 Jul. 2008

(MRAC 227144); 2 33 , U, 10 Get. 2008 (MRAC 227145); 1 3 , 10 Nov. 2008 (INECN); 1 3 , 25

Mar. 2008 (INECN). - 2.86435°S, 29.49546E, site 6, forest with Carapa grandiflora and Polyscias

Figs 30-34. Holmelgonia bosnasutus sp. nov. {3 holotype, $ paratype 227507). 30. Palp, 3 , retrolateral

view. 31. Palpal tibia, 3 , dorsal view. 32. Palpal tibia, 3 , prolateral view. 33. Embolie division of 3 palp,

ventrolateral view. 34. Epigyne, ventral view. Seale bars = 0.1 mm.

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

fulva, 2150 m: 1 S, 10 Sep. 2008 (INECN). - 2.86455°S, 29.50427°E, site 4, forest with Macaranga

neomildbraediana diwdiPolyscias fulva, 2352 m.- 1 10 Jul. 2008 (MRAC 227137); 1 S, 25 May 2008

(MRAC 227194); Iff, 25 Dee. 2008 (INECN); 1 S, 25 Jan. 2008 (INECN). - 2.87060° S, 29.49669°

E, site 2, forest with Hagenia abyssinica, 2548 m: 1 (J, 10 Jul. 2008 (MRAC 227195); 1 25 Apr. 2008

(MRAC 227196); 1 25 Jul. 2008 (INECN); 1 10 Sep. 2008 (INECN). - 2.87696°S, 29.49709°E,

site 1, Philippia benguelensis, 2650 m: 1 25 Nov. 2008 (INECN).

Description

Male (holotype, Figs 6, 9, 17-19, 30-33)

Measurements. Total length 2.00, earapaee 0.88 long, 0.70 wide.

Cephaeothorax. Carapaee greyish brown with blaek striae radiating from fovea; with pale area behind

posterior eyes, followed by reetangular spot from whieh two striae run towards the PEE. Chelieerae

eoloured as earapaee, retromargin with 5 teeth; promargin with 5 small teeth. Clypeus 2.80 times AEE.

Sternum 0.54 long, 0.44 wide, dark greyish brown, shield-shaped.

Eyes. Oeular area blaek. Anterior eye row straight, posterior eye row strongly proeurved. AME 0.03,

AEE 0.08, PME 0.08, PEE 0.08.

Eegs. Yellow to greyish yellow; femora without dorsal spines, but with ventral spines in two rows.

Metatarsi with dorsal spines.

Eeg measurements

Legs

Total

0.90

0.20

0.84

0.60

3.44

0.64

0.18

0.58

0.74

0.62

2.76

111

0.60

0.16

0.60

0.64

0.54

2.54

0.72

0.14

0.58

0.94

0.60

2.98

Eeg chaetotaxy

Legs

Tibial

spines

Proximal

Distal

Position

Eength/DT

Position

Eength/DT

0.38

0.18

2.75

0.75

1.75

0.42

0.20

3.25

0.70

2.00

111

0.54

0.20

3.25

0.38

0.30

3.00

Abdomen. Oval, dark greyish brown, with nine thin, pale transverse lines. Venter dark brown. Spinnerets

pale greyish, short, eonieal.

Paep (Figs 6, 9, 30-33). Retrolateral tibial apophysis with sharp tip and undulated lateral margins,

eaeh undulation provided with a hair; laterally with short, broad prolateral apophysis with blunt tip.

Paraeymbium with broad proximal arm and distal arm with smoothly rounded tip. Proximal part of

tegulum with ventrolateral, oblique grooves. Embolie division with short eurved embolus, long sharp

ventral appendage, sinuous, frontal appendage with sharp tip and long, broad, rounded dorsal appendage.

European Journal of Taxonomy 77 : 1-18 ( 2014 )

Female (paratype, MRAC 227507, Figs 20-22, 34, 40)

Very similar to male.

Measurements. Total length 2.13. Carapaee 0.90 long, 0.72 wide.

Cephaeothorax. Clypeus 3.0 times ALE. Sternum 0.49 long, 0.49 wide.

Eyes. As in male: AME 0.03, AEE 0.08, PME 0.08, PEE 0.08.

Eegs. TM: 1: 0.41,11: 0.40, 111: 0.50.

Eeg measurements

Legs

Total

0.90

0.20

0.80

0.74

0.60

3.24

0.66

0.12

0.54

0.68

0.60

2.60

111

0.70

0.14

0.42

0.60

0.50

2.36

0.78

0.14

0.34

0.82

0.42

2.50

Epigyne (Figs 34, 40). With two holes at posterior margin, resembling the shape of a eow’s nose.

Copulatory duets short, eurved, originating from triangular atrium near posterior margin; entering

spermatheeae near lateral margin, spermatheeae oval, longest axis longitudinal.

Distribution

Known only from the type loeality, Mt Musumba in Kibira National Park (Fig. 1).

Holmelgonia disconveniens sp. nov.

um:lsid:zoobank.org:aet:2787FB55-2335-4C64-BFB8-ABC0825A7F56

Figs 2-3, 7, 10, 23-25,35-38

Diagnosis

The male is eharaeterized by the triangular dorsal tibial apophysis, with a tooth at the tip and sinuous

prolateral margin, by the fairly large, sharp, selerotized prolateral apophysis, and by the paraeymbium

without hairs, its distal arm with a well delimited knob.

Etymology

The speeifie name 'disconveniens ’refers to the eontrasting tinge of dark body and pale legs.

Material examined

Holotype

BURUNDI: S, Pare National de la Kibira, Rwegura, Mt Musumba, 2.86435° S, 29.49540° E, site 1, tea

plantation, 10 Sep. 2008, 2100 m, pitfalls, B. Nzigidahera eoll. (MRAC 229928).

Paratypes

BURUNDI: 1 S, 10 Sep. 2008, same data as for holotype (MRAC 229929). -2.86435° S, 29.49546° E,

site 6, forest with Carapa grandiflora din&Polyscias fulva, 2150 m: 1 S, 10 Aug. 2008 (MRAC 229741);

1 S, lOSep. 2008 (MRAC 229740).-2.86435°S,29.49540°E, site 7, tea plantation, 2100 m, site 7: 1 S,

10 Sep. 2008 (MRAC 241448); 1 S, 10 Sep. 2008 (MRAC 241449). -2.86455° S, 29.50427° E, site 4,

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

forest with Macaranga neomildbraediana and Polyscias fulva, 2352 m:2 33, 25 Nov. 2008 (INECN);

I 3,10 Jan. 2009 (INECN); 4 33 , 25 Aug. 2008 (MRAC 227149); 1 3 , 25 Jun. 2008 (MRAC 227150).

Description

Male (holotype, Figs 7, 10, 23-25, 35-38)

Measurements. Total length 1.8, earapaee 0.80 long 0.70 wide.

Cephaeothorax. Carapaee dark brown, with faint dark striae radiating from fovea; striae larger towards

the margin; a faint pale semieireular area behind eyes formed by two brown bands originating behind

PEE, eonneeted in front of fovea. Chelieerae yellowish brown. Retromargin with 4 teeth; promargin

with 5 small teeth. Clypeus grey, 2.33 times AEE. Sternum 0.56 long, 0.50 wide, dark brown, shield¬

shaped.

Eyes. Oeular area blaek. Anterior eye row reeurved, posterior eye row strongly proeurved; AME 0.05,

AEE 0.08, PME 0.07, PEE 0.07.

Eegs. Pale yellow, tarsi and metatarsi pale grey, femora without dorsal spines, with ventral spines in two

rows. Metatarsi without dorsal spines.

Figs 35-38. Holmelgonia disconveniens sp. nov. {3 holotype). 35. Palp, retrolateral view.

36. Palpal tibia, dorsal view. 37. Palpal tibia, dorsolateral view. 38. Embolie division of palp, ventrolateral

view. Seale bars = 0.1 mm.

European Journal of Taxonomy 77: 1-18 (2014)

Leg measurements

Legs

Total

0.70

0.22

0.58

0.56

0.48

2.54

0.66

0.22

0.56

0.42

2.42

111

0.60

0.20

0.50

0.52

2.32

0.76

0.22

0.64

0.70

0.56

2.88

Eeg chaetotaxy

Legs

Tibial

spines

Proximal

Distal

Position

Eength/DT

Position

Eength/DT

0.55

0.12

0.60

0.40

1.00

0.42

0.18

0.60

0.44

1.00

111

0.40

0.12

3.00

0.45

0.12

3.25

Abdomen. Oval, greyish black, with faint central dark brown band and small pale points, with six

transverse pale chevrons in posterior half Spinnerets yellowish grey, conical.

Paep (Figs 7, 10, 35-38). Dorsal tibial apophysis triangular, with two teeth near tip; retrolateral tibial

apophysis almost as long as dorsal one, ending in sharp, slightly curved tip. Paracymbium with proximal

arm without hairs; distal arm ending in well delimited, rounded knob. Subtegulum with transverse ventral

grooves. Embolic division with short, curved embolus, posterior appendage very short and smoothly

rounded; dorsal appendage triangular; frontal appendage short, club-shaped, with frontal margin with

many small teeth.

Female

Unknown.

Distribution

Known only from the type locality (Fig. 1).

Figs 39-40. — 39. Holmelgonia afromontana sp. nov. ($, 227154). Epigyne, cleared, dorsal view. —

40. Holmelgonia bosnasutus sp. nov. ($, 227507). Epigyne, cleared, dorsal view. Scale bars = 0.1 mm.

NZIGIDAHERAB. & JOCQUE R., Holmelgonia from the Albertine Rift

Discussion

Linyphiidae are a striking example of a family in whieh genera have been ereeted based on seeondary

sexual eharaeters that appear to be speeies speeifie. This phenomenon was diseussed in Joeque et al.

(2013), who argued that genera in some families are partieularly diffieult to define when they eontain

so-ealled ‘templates’ (as defined by Joeque & Bosselaers 2011), laeking elear somatie autapomorphies.

The definition of Holmelgonia is no exeeption to this: apart from the absenee of stridulating files on the

ehelieerae, no somatie eharaeters eould be found to define it. Even the ehaetotaxy, and more speeifieally

the position of the metatarsal triehobothria, varies to an extent that is unusual in erigonine genera. The

genus has therefore to be defined on the base of features of the seeondary genitalia. The palp has a tibia

with a dorsal proeess and the ED is rather eomplex, with several protuberanees. Yet, in two of the speeies

deseribed here the ED is fairly simple. The latter feature, however, is not restrieted to Holmelgonia

and ean be found in many genera in the Erigoninae. It thus remains questionable whether the speeies

attributed to Holmelgonia really do eonstitute a natural group.

This study is a result of the intense sampling of ground spiders earried out in the forest eeosystems of

western Burundi during several years (2003, 2005 and 2008). The three speeies deseribed here were

only found in the mountain forest of Kibira National Park. Holmelgonia bosnasutus sp. nov. oeeupies

a wide altitudinal gradient, ranging from 2100 to 2650 m. The speeies H. afromontana sp. nov. and H.

disconveniens sp. nov. are eonfined to a narrower altitudinal zone between 2100 and 2352 m.

This study shows again that the Albertine Rift in Central Afriea has only been superfieially explored

with regard to its spider fauna. This was already elear with the diseovery of speeies swarms in the

Gnaphosidae, in whieh the genera Zelotibia Russell-Smith & Murphy, 2005 (20 speeies) and Zelowan

Murphy & Russell-Smith, 2010 (18 speeies) were found to have radiated in that mountain range (Russell-

Smith & Murphy 2005; Murphy & Russell-Smith 2010; Nzigidahera & Joeque 2009). Further studies in

preparation show that similar radiations ean be expeeted in other genera of the Einyphiidae and in other

families sueh as the Tetragnathidae, partieularly in ground-living genera that have lost the web-building

habit. There is a eonsiderable urgeney to deseribe the fauna in this region, where human populations are

expanding rapidly and deforestation is eonsequently very intense.

Acknowledgements

ABIC (Afriean Biodiversity Information Centre) of the Royal Museum for Central Afriea and GBIF are

thanked for several travel grants to BN. We are indebted to the Royal Museum for Central Afriea for

aeeommodation for BN during his studies in Belgium. We thank Alain Reygel, who made the drawings

with his usual skill. We thank two anonymous reviewers for improvements to the first version.

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Manuscript received: 5 September 2013

Manuscript accepted: 8 November 2013

Published on: 17 March 2014

Topic editor: Koen Martens

Desk editor: Danny Eibye-Jacobsen

Printed versions of all papers are also deposited in the libraries of the institutes that are members of

the EJT eonsortium: Museum National d’Histoire Naturelle, Paris, Franee; National Botanie Garden

of Belgium, Meise, Belgium; Royal Museum for Central Afriea, Tervuren, Belgium; National History

Museum, London, United Kingdom; Royal Belgian Institute of Natural Seienees, Brussels, Belgium;

Natural History Museum of Denmark, Copenhagen, Denmark.