Spinirta sparsula sp. nov. (ẅḦẊĦ)

Figs 2 A–C, 3C, 11–13

Type material. Holotype: ♂, CHINA: Hunan Province, Sangzhi County, Bamaoxi Township, Xiaozhuangping Village, Tianping Mountain (29°47.157′N, 110°05.841′E), 1330 m a.s.l., 15 September 2015, leg. Chi Jin, Xiangbo Guo & Jingchao He. Paratypes: 1♀, same data as holotype .

Etymology. The specific name is from the Latin word sparsula, meaning “sparse”, referring to the sparse spines on the ventral surface of the RTA.

Diagnosis. The male can be distinguished from other congeners by: 1) RTA with a digitiform apex and kidneyshaped protrusion at the base (Figs 12C, F), and 2) ventral surface of RTA only with a few slender spines (Fig. 12F). The female resembles S. qiaoliaoensis (Lu & Chen, 2019) comb. nov. in having a similar atrium formed by the incomplete fusion of two enlarged COs (Fig. 12G; Lu et al. 2019: fig. 2D), but can be distinguished from it by: 1) the posterior margin of the atrium closer to the margin of the epigyne than in S. qiaoliaoensis (Fig. 12G; Lu et al. 2019: fig. 2D), and 2) the distance between the spermathecae is obviously larger than that in S. qiaoliaoensis (Fig. 12H; Lu et. al. 2019: fig. 2C).

Description. Male (Figs 2 A–C, 3C, 11A–D, 12A–F, 13A–D). Holotype: body 9.60 long: carapace 4.77 long, 3.76 wide, width: length= 0.79; abdomen 4.83 long, 3.34 wide. Diameters of eyes: AME 0.28, ALE 0.24, PME 0.28, PLE 0.26. Eye interdistances: AME–AME 0.15, AME–ALE 0.10, ALE–ALE 0.96, PME–PME 0.25, PME–PLE 0.33, PLE–PLE 1.40, ALE–PLE 0.16. OAW 1.62, CRW 2.31, OAW/CRW = 0.70. CRW/carapace width = 0.61. MOA 0.63 long, front width 0.70, back width 0.72. Clypeus height 0.33, 1.18 times AME diameter. Chelicerae with three promarginal teeth and five retromarginal teeth. Labium 0.81 long, 0.66 wide. Sternum 2.21 long, 1.99 wide. Measurements of legs: leg I 13.63 (3.84 + 1.65 + 3.26 + 3.05 + 1.83), II 12.78 (3.70 + 1.56 + 3.07 + 2.81 + 1.64), III 11.20 (3.13 + 1.46 + 2.44 + 2.69 + 1.48), IV 14.94 (3.95 + 1.58 + 3.57 + 4.20 + 1.64).

Palp as illustrated (Figs 3C, 12 A–F, 13A–D). Tibial ventral protrusion digitiform, with blunt apex. RTA with digitiform apex and kidney-shaped protrusion at base; ventral surface only with few slender spines. PTA triangular. Tegulum retrolateral apex low and round. Subtegulum with two transverse grooves on prolateral surface. Embolus with round extension on retrolateral side, with short, spine-like tip; embolar apophysis with truncated tip, with obvious file-like grooves on surface.

Female (Figs 11 E–H, 12G, H, 13E, F). Paratype: body 11.08 long: carapace 4.56 long, 3.53 wide, width: length = 0.77; abdomen 6.52 long, 4.94 wide. Diameters of eyes: AME 0.25, ALE 0.20, PME 0.23, PLE 0.24. Eye interdistances: AME–AME 0.19, AME–ALE 0.10, ALE–ALE 0.90, PME–PME 0.19, PME–PLE 0.28, PLE–PLE 1.25, ALE–PLE 0.14. OAW 1.52, CRW 2.15, OAW: CRW/0.71. CRW/carapace width = 0.61. MOA 0.51 long, front width 0.66, back width 0.72. Clypeus height 0.29, 1.16 times AME diameter. Chelicerae with three promarginal teeth and five retromarginal teeth. Labium 0.69 long, 0.68 wide. Sternum 2.09 long, 1.90 wide. Measurements of legs: leg I 12.72 (3.53 + 1.57 + 3.12 + 2.82 + 1.68), II 12.00 (3.49 + 1.42 + 2.84 + 2.70 + 1.55), III 10.49 (2.94 + 1.26 + 2.34 + 2.62 + 1.33), IV 14.44 (3.91 + 1.52 + 3.43 + 3.94 + 1.64).

Epigyne weakly sclerotized, likely because specimen had recently moulted before being collected (Figs 12G, 13E): anteriorly with an atrium formed by incomplete fusion of two enlarged oval COs. Vulva (Figs 12H, 13F): copulatory ducts anteriorly inflated, running apart backward, anteriorly with large membranous parts; accessory glands small, oval; spermathecae separated by more than spermatheca’s width.

Distribution. China (Hunan) (Fig. 26).