Ptocasius robustus sp. nov.

urn:lsid:zoobank.org:act: F22A884D-56BA-4365-9C9F-B549720B176E

Figs 29–30, 41

Diagnosis

The new species resembles P. nobilis (Żabka, 1981) (Żabka 1981: figs 46–47), but can be distinguished by: (1) the anterior margins of pockets almost located at median area of epigynum in ventral view (Figs 29B, 30A), while close to posterior of epigynum in P. nobilis (Żabka 1981: fig. 46); (2) copulatory openings ()-shaped in ventral view (Figs 29B, 30A), while almost V-shaped in P. nobilis (Żabka 1981: fig. 46); (3) spermathecae robust, twisting outward, distinctly thicker than copulatory ducts in dorsal view (Figs 29C, 30B), while narrow, twisting inward, thinner than copulatory ducts in P. nobilis (Żabka 1981: fig. 47); (4) terminal margins of spermathecae inside copulatory ducts in dorsal view (Figs 29C, 30B), while outside copulatory ducts in P. nobilis (Żabka 1981: fig. 47).

Etymology

The specific name is derived from the Latin adjective ‘ robustus ’ (‘strong’ or ‘robust’), referring to the robust spermathecae.

Type material

Holotype

CHINA • ♀; Yunnan Province, Nujiang Prefecture, Gongshan County, Nujiang State Nature Reserve, Qiqi, 9.9 km West of Gongshan; 27°42′55″ N, 98°33′55″ E; 2000 m a.s.l.; 9–14 Jul. 2000; Heng-mei Yan, David Kavanaugh, Charles Griswold, Hong-bin Liang, Darrell Ubick and Da-zhi Dong leg.; HNU- 00–QF–7A.

Paratypes (7 ♀♀)

CHINA – Yunnan Province • 7 ♀♀; same collection data as for holotype; HNU-00–QF– 7P.

Description

Female (holotype)

BODY AND HEAD. Total length 4.10. Prosoma 1.90 long, 1.50 wide. Opisthosoma 2.20 long, 1.30 wide. Clypeus height 0.10. Carapace (Fig. 29A) light brown, sparsely covered with long brown hairs; eyes base black; ocular area grayish brown, with a pair of grayish black bar-shaped markings, anterior and lateral margins grayish black, covered with dense white hairs. Fovea reddish brown. Radial groove indistinct. Eye diameter and interdistances: AME 0.45, ALE 0.23, PLE 0.20, AERW 1.30, PERW 1.30, EL 0.85. Sternum oval, light yellowish brown, covered with thin brown hairs. Clypeus brown, densely covered with long white hairs and brown hairs. Endites and labium yellowish brown, distal area covered with grayish black hairs, labium black, almost triangular.

CHELICERAE (Fig. 30C). Light yellowish brown, with two short and robust promarginal teeth and one retromarginal denticle.

LEGS. Light yellowish brown, sparsely covered with hairs; bearing numerous thin spines. Tibiae I and II with three pairs of long ventral spines, metatarsi I and II with two pairs of long ventral spines.

LEG MEASUREMENTS. I = 3.20 (1.00, 1.25, 0.50, 0.45), II = 3.10 (1.00, 1.20, 0.50, 0.40), III = 3.65 (1.10, 1.25, 0.80, 0.50), IV = 3.95 (1.20, 1.40, 0.80, 0.55). Leg formula: IV–III–I–II.

ABDOMEN (Fig. 29A). Long oval, the posterior portion slightly wide. Dorsum yellowish brown with two pairs of reddish brown sigillae; each side with a grayish brown longitudinal band and irregular black longitudinal markings; the posterior median area with black arc markings; ventral yellowish brown, the median area with three black longitudinal bands. Spinnerets grayish brown.

EPIGYNUM (Figs 29B–C, 30A–B). Almost wider than long; the pockets angular, distinctly diverging in dorsal view, the pockets located at the medial area of epigynum; copulatory openings almost ()-shaped; spermathecae twisted and robust, the top margins of spermathecae close to copulatory openings.

Male

Unknown.

Distribution

China (Yunnan Province, Fig. 41).