Callosa, Zhao, Qingyuan & Li, Shuqiang, 2017

Zhao, Qingyuan & Li, Shuqiang, 2017, Callosa gen. n., a new troglobitic genus from southwest China (Araneae, Linyphiidae), ZooKeys 703, pp. 109-128 : 109

Genus Callosa gen. n.

Type species.

Callosa ciliata sp. n.

Etymology.

The generic name is an arbitrary combination of letters. Gender is feminine.

Diagnosis.

The copulatory organs in this genus clearly resemble those in Porrhommini , but differ from the similar genera by: embolus in Callosa gen. n. is long and forms one big loop (Figs 1A, 5A), neither a short and curved one as in Porrhomma Simon, 1884, Diplostyla Emerton, 1882, Pacifiphantes Eskov & Marusik, 1994 ( Roberts 1987: figs 58 a–e, 59 a–e; Eskov and Marusik 1994: fig. 42), nor an apically coiled one as in most Bathyphantes Menge, 1866 ( Roberts 1987: fig. 70 a–e); the embolus in Bathyphantes approximatus (O. Pickard-Cambridge, 1871) is longer and slimmer, forming more than 2 loops ( Ivie 1969: fig. 102); Microbathyphantes Helsdingen, 1985 has coiled, whip-like, and fully exposed embolus ( Tu and Li 2006: fig. 2C), unlike the one enveloped in a membranous plate of the convector in Callosa gen. n. The epigyne in Callosa gen. n. is distinguished by its long, spiraling copulatory furrows and the presence of a septum (Figs 3C, 7C); the receptacles are situated farther from atrium in most Bathyphantes species, furrows are not in double-helix; Kaestneria Wiehle, 1956 and Pacifiphantes have shorter copulatory furrows, which fold or curve ( Slowik and Blagoev 2012: fig. 6); the copulatory furrows in Microbathyphantes make only half a turn.

Description.

Median size, 2.5‒2.8. Chelicerae with three promarginal, and four retromarginal teeth. AME completely lost, PME reduced to small unpigmented spots, ALE and PLE highly reduced (Figs 2C, 2E, 3D, 3F, 6C, 6E, 7D, 7F); ocular area with several rows of short setae (Figs 2C, 6C). Carapace length/leg I 0.13- 0.15. Coxae IV separated by their diameter. Chaetotaxy: 2-2-2-2. TmI 0.15-0.20, TmIV absent. Leg formula I-II-IV-III. Legs yellow without obvious patterns.

Male palp: femur about four times longer than patella; tibia with two trichobothria, one ventral and one retrolateral (Fig. 5B). Cymbium spindle-shaped at dorsal view (Figs 2A, 6A); Paracymbium ‘J’ -shaped, stout at base, attenuated and curved at apex (Figs 1B, 5B). Bulb with an oblate subtegulum and a protruding protegulum (Figs 1B, 5B). Convector with a membranous plate enveloping the prolateral side of embolic division (Figs 1A, 5A), and a ribbon-like ventral process (Figs 1B, 2B, 5B, 6B); dorsal projection of convector situated near the base of cymbium in prolateral view (Figs 1A, 5A); distal suprategular apophysis pick-like, broad at base, hooked at apex (Figs 1D, 5D); median membrane with dense membranous short cilia (Figs 4B, 8B); embolus long and belt-like, with a tapering tip, making 1.5 loops along the exterior margin of convector plate (Figs 1A, 5A).

Epigyne : dome-shaped in lateral view, with atrium fully exposed in ventral view (Figs 3A, 4 C–D, 7A, 8 C–D); septum stretched along the axis of atrium; parmula short with a shallow socket near tip (Figs 4D, 8C); copulatory furrows making a spiral course (Figs 3C, 7C); receptacles oval, with short, tube-like processes (Figs 3C, 7C).

Species composition.

Two species, Callosa ciliata sp. n. (type species) and Callosa baiseensis sp. n.

Distribution.

Yunnan Province and Guangxi Zhuang Autonomous Region, China (Fig. 9).