Nescina Ballarin & Li, 2015

Lin, Yucheng, Ballarin, Francesco & Li, Shuqiang, 2016, A survey of the spider family Nesticidae (Arachnida, Araneae) in Asia and Madagascar, with the description of forty-three new species, ZooKeys 627, pp. 1-168 : 9-10

Taxon classification Animalia Araneae Nesticidae

Genus Nescina Ballarin & Li, 2015

Nescina Ballarin & Li, 2015: 183.

Type species.

Nescina minuta Ballarin & Li, 2015 from Yunnan, China.

Diagnosis.

Males of Nescina are distinguished from those of the other genera of Nesticidae with the exception of Hamus and Wraios by a short and very simple paracymbium having only a lobed ventral apophysis (Va) and a sclerotized, hook-shaped distal process (Dp), by the almost round, ventrally flat bulb and by the elongate, laminar conductor (C) with only one small process (Cp-I). Males of Nescina can be separated from those of Hamus by the smaller terminal apophysis II (Ta-II) and the reduced, laminar process I of the conductor (Cp-I), and from those of Wraios by the shape of embolus. Diagnostic characters for the females are the long and twisted fertilization ducts (Fd) which have no similarities in the other genera. Furthermore Nescina is easily distinguished by the remarkably small size of the adults (total length less than 1.60) and the protruding cephalic area clearly separated from the thoracic area by a distinct cervical groove.

Description.

Total length: 1.30-1.56 (male), 1.44-1.57 (female). Carapace ovate, pale yellow. Cephalic area strongly elevated and clearly differentiated from the rest of the carapace. Eyes ALE=PLE>PME>AME, AER and PER procurved, MOA square. Cervical groove and fovea indistinct. Chelicera with six promarginal teeth and two retromarginal tiny denticles on the fang furrow. Sternum yellowish, heart-shaped. Opisthosoma yellowish, usually with four darker marks more or less visible. Spinnerets and colulus pale yellow.

Male palp: tibia short, as long as wide, with two retrodorsal trichobothria and several long setae. Cymbium almost round with long setae and long furrow on the retrolateral margin. Paracymbium simple, with a wide, lobed ventral apophysis and a hook-like distal process bent ventrally. Bulb ventrally flat. Terminal apophysis small and flat with two processes, Ta-I laminar, Ta-II spur-like. Tegular apophysis missing. Conductor laminar and long, starting from the anterior margin of the tegulum and following the embolus on the prolateral side with a counterclockwise course. One laminar process (Cp-I) at the subapical margin. Embolus filamentous starting from the retrolateral side of the bulb and continuing bordering the tegulum with a semicircular clockwise course.

Epigyne: wide, copulatory openings located near the epigynal posterior margin. Spermathecae and fertilization ducts can be observed through the transparent tegument. Spermathecae wide and globular, fertilization ducts long and twisted, laterally oriented. Copulatory ducts short.

Composition.

Nescina minuta Ballarin & Li, 2015 and Nescina kohi sp. n.

Distribution.

China (Yunnan), Singapore (Fig. 81).