Ptocasius geminus sp. nov.

urn:lsid:zoobank.org:act: 33D1E30D-1B0C-4A6B-8DF1-45B602413528

Figs 15–17, 44

Diagnosis

The male of the new species resembles that of P. falcatus (Zhu et al., 2005) (Zhu et al. 2005: fig. 13d–e) in having a similar morphology of the male palp, but can be distinguished by: (1) genital bulb distinctly longer than wide in ventral view (Figs 15B, 17A), while almost as long as wide in P. falcatus (Zhu et al. 2005: fig. 13d); (2) genital lobe thumb-shaped in ventral view (Figs 15B, 17A), while somewhat rectangular in P. falcatus (Zhu et al. 2005: fig. 13d); (3) tibial apophysis knife-shaped in retrolateral view (Figs 15C, 17B), while finger-shaped in P. falcatus (Zhu et al. 2005: fig. 13e). The female of the new species resembles that of P. falcatus (Zhu et al. 2005: fig. 13a–c) in having a similar morphology of the epigynum, but can be distinguished by: (1) top of pockets below posterior margin of copulatory openings in ventral view (Figs 16B, 17D), while anterior margin present between copulatory openings in P. falcatus (Zhu et al. 2005: fig. 13b); (2) posterior margin of pockets two times as wide as long in ventral view (Figs 16B, 17D), while as long as wide in P. falcatus (Zhu et al. 2005: fig. 13b).

Etymology

The specific name is derived from the Latin adjective ‘ geminus ’ (‘twin-born’), referring to the form of epigynum pockets.

Type material

Holotype

CHINA • ♂; Yunnan Province, Nujiang Prefecture, Gongshan County, Danzhu, 15.7–16.0 km Southwest of Gongshan; 27°37′37″ N, 98°35′31″ E to 27°37′19″ N, 98°35′14″ E; 2800–3425 m a.s.l.; 2 Jul. 2000; Heng-mei Yan, David Kavanaugh, Charles Griswold, Hong-bin Liang, Darrell Ubick and Da-zhi Dong leg.; HNU-00–GDS–2A.

Paratypes (14 ♁♁, 18 ♀♀)

CHINA – Yunnan Province • 4 ♀♀; same collection data as for holotype; HNU-00–GDS–2P • 10 ♂♂, 9 ♀♀; Nujiang Prefecture, Nujiang State Nature Reserve, No. 12 bridge Camp area, 16.3 km West of Gongshan; 27°42′54″ N, 98°30′08″ E; 2775 m a.s.l.; 15–17 Jul. 2000; Heng-mei Yan, David Kavanaugh, Charles Griswold, Hong-bin Liang, Darrell Ubick and Da-zhi Dong leg.; HNU-Yan000715 • 1 ♂; 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–5 • 3 ♂♂, 5 ♀♀; Nujiang Prefecture, Gongshan County, Danzhu, 13.5 km Southwest of Gongshan; 27°37′50″ N, 98°37′14″ E; 2700 m a.s.l.; 30 Jun.–5 Jul. 2000; David Kavanaugh, Charles Griswold, Hong-bin Liang, Darrell Ubick, Heng-mei Yan and Da-zhi Dong leg.; HNU-Yan000730 .

Description

Male (holotype)

BODY AND HEAD. Total length 4.60. Prosoma 1.80 long, 1.40 wide. Opisthosoma 2.80 long, 1.30 wide. Clypeus height 0.10. Carapace (Fig. 15A) dark brown, carapace margin and eyes base black, anterior and lateral margins black; anterior and lateral margins of ocular area black with dense white hairs; PLE followed by two small slightly colored circles. Fovea thin, reddish brown, radial groove black, line-shaped. Eye diameter and interdistances: AME 0.40, ALE 0.20, PLE 0.20, AERW 1.20, PERW 1.10, EL 0.80. Sternum inverse pear-shaped, highly bulged, densely covered with fine brown hairs; yellowish brown, margin black. Clypeus dark brown, sparsely covered with long brown hairs; promargin black, sides light brown. Endites and labium brown, distal area covered with light grayish black hairs.

CHELICERAE (Fig. 17C). Brown, anterolateral area black, two large promarginal teeth and one small retromarginal denticle.

LEGS. Light brown to brown, with black markings or annuli; spines short. Tibiae I and II with three pairs of long ventral spines, metatarsi I and II with two pairs of ventral spines.

LEG MEASUREMENTS. I = 3.30 (1.00, 1.30, 0.50, 0.50), II = 2.95 (0.95, 1.10, 0.45, 0.45), III = 3.35 (1.00, 1.10, 0.70, 0.50), IV = 3.70 (1.20, 1.20, 0.80, 0.50). Leg formula: IV–III–I–II.

ABDOMEN (Fig. 15A). Oval, dorsum anterior margin black; cardiac marking bar-shaped, grayish black, with two pairs of sigillae; the posterior median with two large black herring bones; sides with some irregular black twills, ventral light yellow, the median area with small black spots, sides with many black twills; the posterior area with a big black marking. Spinnerets dark brown.

PALP (Figs 15B–C, 17A–B). Longer than wide; embolus originates at about 8:00 o’clock position; genital bulb with a membranous structure; genital lobe thumb-shaped in ventral view; tibial apophysis knife-shaped.

Female (paratypes)

BODY AND HEAD. Total length 5.60. Prosoma 2.10 long, 1.60 wide. Opisthosoma 3.50 long, 2.40 wide. Eye diameter and interdistances: AME 0.40, ALE 0.25, PLE 0.25, AER 1.35, PER 1.30, EFL 0.90. 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 = 3.40 (1.10, 1.30, 0.50, 0.50), II = 3.10 (1.00, 1.20, 0.50, 0.40), III = 3.80 (1.20, 1.30, 0.70, 0.60), IV = 4.50 (1.40, 1.50, 1.00, 0.50). Leg formula: IV–III–I–II.

ABDOMEN (Fig. 16A). Mid-ventrally with a grayish black longitudinal band. Markings and other morphological features the same as in male.

EPIGYNUM (Figs 16B–C, 17D–E). Almost as long as wide; the pockets almost touching, present below the copulatory openings; copulatory openings almost transverse; copulatory ducts cylindrical; spermathecae spiral, close to each other.

Distribution

China (Yunnan Province, Fig. 44).