Xizangiana namchabarwa Liu & Zhang, sp. n.

(NJḇƃffiqǥ)

Figs 1A, 2C–D, 3C, 6C–D, 7–8

Type material. Holotype ♁ (MHBU-ARA- 2022-26-1), CHINA: Xizang Autonomous Region, Linzhi City, Mainling County, Pai Town, 29.511514°N, 94.879380°E, 2945 m elev., 3 June 2022, leg. Bo Liu. Paratype: 3♀ (MHBU-ARA- 2022-26-2 to 4), same data as holotype; 1♀ (MHBU-ARA- 2022-24-1), CHINA: Xizang Autonomous Region, Linzhi City, Bayi District, Lulang Town, 30.003218°N, 94.900765°E, 2326 m elev., 2 June 2022, leg. Bo Liu ; 11♀ (MHBU-ARA-005586 to 5596), CHINA: Xizang Autonomous Region, Linzhi City, Lang County, 20 August 2002, leg. Minshen Zhu & Feng Zhang.

Etymology. The species name comes from “Namchabarwa”, the highest mountain peak in the easternmost area of the Himalaya, which is shrouded in mist all year round and difficult to see the peak, referring to both the type locality, which is at the foot of the Namchabarwa, and to the membranous projection that is hard to see (Fig. 3C); noun in apposition.

Diagnosis. This new species resembles X. linzhiensis in genitalic structures, but can be distinguished by retrolateral tibial apophysis shark-fin-shaped, with a blunt triangular membranous projection dorsally (Fig. 3C; vs. retrolateral tibial apophysis finger-shaped, with arc-shaped membranous projection dorsally in X. linzhiensis, Fig. 3A), the presence of embolar base bump (Fig. 8F; vs. embolar base bump absent in X. linzhiensis, Fig. 5C) in males, and the small body (comparatively large in X. linzhiensis), the relatively large scape, almost two time length of primary spermathecae (Fig. 6C; vs. scape relatively small, almost length of primary spermathecae in X. linzhiensis, Fig. 6A), transversal folds slightly curved (Fig. 6D; vs. strongly curved in X. linzhiensis, Fig. 6B), and the trapezoidal atrium (Fig. 6C; vs. triangular atrium in X. linzhiensis, Fig. 6A) in females.

Description. Male. Holotype (Fig. 7A–B; MHBU-ARA- 2022-26-1): total length 3.70; carapace 1.93 long, 1.45 wide; abdomen 1.77 long, 1.28 wide. Eye sizes and interdistances:AME 0.07, ALE 0.10, PME 0.06, PLE 0.07; AME‒AME 0.05, AME‒ALE 0.01, PME‒PME 0.06, PME‒PLE 0.06, ALE‒PLE 0.04. Leg measurements: I 5.52 (1.46, 0.77, 1.32, 1.11, 0.86), II 3.85 (1.09, 0.53, 0.89, 0.75, 0.59), III 3.50 (0.98, 0.40, 0.74, 0.82, 0.56), IV 5.27 (1.34, 0.61, 1.14, 1.36, 0.82). Leg formula: 1423. Cheliceral promargin with three teeth, retromargin with two (Fig. 2D). Color in alcohol (Fig. 7A–B): carapace dark brown; legs yellow-brown.

Palp (Figs 3C, 8). Retrolateral tibial apophysis shark-fin-shaped, with a blunt triangular membranous projection dorsally; embolar radix with an arc-shaped projection distally; embolar base with a branched bump and distoventrally with a relatively long, curved embolar base projection; embolus curved ventrally; median apophysis wide at base, narrowest at median part, almost 3 times thinner than base.

Female. Total length 3.30–4.74. One paratype (Fig. 7C–D; MHBU-ARA- 2022-26-2): total length 3.39; carapace 1.62 long, 1.15 wide; abdomen 1.77 long, 1.17 wide. Eye sizes and interdistances: AME 0.07, ALE 0.09, PME 0.07, PLE 0.07; AME‒AME 0.05, AME‒ALE 0.02, PME‒PME 0.08, PME‒PLE 0.05, ALE‒PLE 0.06. Leg measurements: I 3.82 (1.23, 0.49, 0.87, 0.64, 0.59), II 2.82 (0.80, 0.41, 0.65, 0.48, 0.48), III 2.97 (0.88, 0.42, 0.69, 0.48, 0.50), IV 4.24 (1.18, 0.47, 0.87, 1.04, 0.68). Leg formula: 4132. Chelicerae (Fig. 2C) as in male. Color in alcohol (Fig. 7C–D) as in male.

Epigyne (Fig. 6C–D). Atrium almost trapezoid-shaped with six transversal folds; scape relatively large, with a ratio of length to width less than 1.5; anterior fold well sclerotized; lateral folds almost triangular-shaped, well sclerotized; secondary spermathecae oval, small.

Distribution. China (Xizang) (Fig. 23).