Bifurcia shuangqiao sp. nov.

Figs 10, 11, 12, 16 G, I

Type material.

Holotype ♂ (IZCAS - Ar 44932) and paratype 1 ♀ (IZCAS - Ar 44933), Shuangqiaogou (31 ° 7.34 ' N, 102 ° 46.71 ' E), Siguniangshan National Scenic Area, Siguniangshan Town, Xiaojin County, Aba Tibetan and Qiang Autonomous Prefecture, Sichuan, China, 02 / 08 / 2004, Lihong Tu leg.

Etymology.

The specific name refers to the type locality; noun in apposition.

Diagnosis.

The new species resembles B. curvata (Sha & Zhu, 1987) (Saaristo et al. 2006: figs 9–17) with similar large chitinized basal part of median membrane (CPM) and epigyne (Figs 10 B, 11 A, 16 G, I), but can be distinguished by embolus with hooked apex (AX) (Fig. 16 G vs. sharp, Saaristo et al. 2006: fig. 12), by anterior terminal apophysis (ATA) finger-shaped (Figs 10 A, 16 G vs. handle-shaped, Saaristo et al. 2006: figs 11, 12), by lamellar extension of pseudolamella (LE) absent (Figs 10 C, 16 G vs. present and ribbon-shaped, Saaristo et al. 2006: figs 10, 12), and by posterior part of posterior median plate (PMP) straight (Fig. 11 C vs. curved, Saaristo et al. 2006: fig. 17).

Description.

Male (holotype). Total length: 1.78, carapace 0.88 long, 0.78 wide, abdomen 0.89 long, 0.62 wide. Eye inter-distances and diameters: AME 0.05, AME-AME 0.02, ALE 0.08, AME-ALE 0.06, PME 0.08, PME-PME 0.04, PLE 0.08, and PME-PLE 0.04. Sternum 0.53 long, 0.51 wide. Clypeus 0.12 high. Chelicerae promargin with 3 teeth, retromargin with 4 teeth. Length of legs: I 5.43 (1.41, 0.28, 1.48, 1.34, 0.92), II 4.63 (1.24, 0.26, 1.21, 1.14, 0.78), III 3.42 (0.97, 0.22, 0.80, 0.83, 0.60), IV 4.47 (1.33, 0.25, 1.13, 1.06, 0.70). Leg formula: I-II-IV-III. TmI 0.15, TmIV absent. Tibial spine formula: 2-2 - 2 - 2. Carapace yellowish-brown. Sternum dark brown. Abdomen with greenish gray dorsal spots (Fig. 12 A, B).

Palp (Fig. 10). Patella with long dorsal bristle. Tibia unmodified. Cymbium with hook-shaped proximal apophysis (PCA) pointing retrolaterally. Paracymbium (P) bifurcate with three branches: proximally short branch, medianly robust branch with round lateral branch and distal branch. Pit hook (PH) on stout distal part of suprategulum (SPT) extremely reduced to small outgrowth. Embolic division (Fig. 16 G, I): anterior part of radix (APR) hook-shaped; sperm duct inside the radix (R) inconspicuous with Fickert’s gland (FG); pseudolamella (PL) strongly sclerotized and lamellar extension (LE) absent. Anterior terminal apophysis (ATA) extending out handle-shaped tip pointing anterodorsally; median terminal apophysis (MTA) membranous with serrated margin; posterior terminal apophysis (PTA) rectangular and strongly sclerotized. Embolus (E) with conical embolus proper (EP), sclerotized thumb (TH), and hooked apex (AX). Median membrane (MM) with large chitinized basal part (CPM).

Female (paratype). Total length: 1.86, carapace 0.95 long, 0.80 wide, abdomen 0.94 long, 1.33 wide. Eye inter-distances and diameters: AME 0.04, AME-AME 0.02, ALE 0.09, AME-ALE 0.05, PME 0.08, PME-PME 0.05, PLE 0.08, and PME-PLE 0.04. Sternum 0.60 long, 0.56 wide. Clypeus 0.10 high. Chelicerae promargin with 3 teeth, retromargin with 5 teeth. Length of legs: I 5.37 (1.48, 0.33, 1.44, 1.28, 0.84), II 4.79 (1.33, 0.31, 1.22, 1.13, 0.80), III 3.70 (1.10, 0.26, 0.88, 0.86, 0.60), IV 4.69 (1.42, 0.27, 1.19, 1.11, 0.70). Leg formula: I-II-IV-III. TmI 0.17, TmIV absent. Tibial spine formula: 2-2 - 2 - 2. Coloration generally as in male (Fig. 12 C, D).

Epigyne (Fig. 11). Basal part of scape (BS) sparsely clothed with long curved hairs, turned under basal part forming large circle. Posterior part of posterior median plate (PMP) curved. Distal part of scape (DPS) T-shaped, laterally directed lateral lobes (LL) extending out of either side in ventral view. Spermathecae (S) S-shaped.

Distribution.

China (Sichuan, type locality; Fig. 1).