Material examined. Holotype ♂ (IZCAS), Vietnam, Ninh Thuan Province, Nui Chua National Park (11º43.565′N, 109º11.135′E), elev. 70 m, 30.VIII.2015, Leg. Q. Zhao, Y. Li & Z. Chen. Paratypes 1♂ 3♀ (IZCAS), same data as holotype.
Etymology. The specific name is derived from the type locality; noun.
Diagnosis. The new species is similar to S. apo Deeleman-Reinhold, 1995, but males can be distinguished by the palpal tibia which is shorter than the cymbium (Figs 36A–B) and the chelicerae which are laterally excavated, with several short, strong setae (Fig. 56H) and females by the very large, balloon-shaped spermathecae (Fig. 37A). S. apo males have the palpal tibia longer than the cymbium, the chelicerae laterally straight, without special setae, and the females have oval spermathecae (Deeleman-Reinhold, 1995: figs 220–224).
Description. Male. Total length 0.93; carapace length 0.47; carapace width 0.38; abdomen length 0.44; abdomen width 0.37. Prosoma: carapace pyriform, narrowing gradually anteriorly; light yellow, suffused with a purplish pattern (Fig. 37C); pars cephalica flat; fovea not visible. Sternum light yellow, suffused with purplish color, as long as wide. Endites light yellow, suffused with purplish tinge; with serrula; labium light yellow, suffused with purplish tinge. Clypeus nearly vertical; short. Chelicerae light yellow, laterally excavated, with several short, strong setae; promargin with a series of six teeth reaching the lamina; retromargin with two very small denticles (Fig. 56H). Eyes: six contiguous eyes surrounded by black pigmentation; PME and ALE subequal, PLE largest (Fig. 37C). Opisthosoma oval; purplish. Legs missing. Genitalia (Fig. 36). Palpal femur long; palpal tibia about 0.7 times as long as cymbium (Figs 36A–B). Cymbium conical, without prolateral extensions. Bulb spherical. Embolus short, dark and basally without distinct associated sclerites; sperm duct very wide, narrowing distally (Fig. 36D).
Female. Total length 1.03; carapace length 0.46; carapace width 0.41; abdomen length 0.55; abdomen width 0.48. Similar to male in color and general features (Figs 37D–E) but larger. Chelicerae unmodified. Legs light yellow; leg formula 4123; leg lengths I 1.78 (0.48, 0.15, 0.53, 0.36, 0.26); II 1.58 (0.45, 0.14, 0.44, 0.32, 0.23); III 1.39 (0.38, 0.11, 0.36, 0.31, 0.23); IV 1.93 (0.54, 0.14, 0.56, 0.42, 0.28). Genitalia. Internal genitalia with afferent spermathecae very short, not extending past the sides of the abdomen (Fig. 37B); spermathecae very large, balloon shaped (Fig. 37A).
Distribution. Known only from the type locality.