Ischnothyreus cristiformis Tong & Li sp. nov. Figures 1, 2, 3, 20A-C, 22A, B, 23A, B

Type material.

Holotype ♂: China, Yunnan, Mengla County, Xiaolongha, Xishuangbanna Biodiversity Conservation Corridor, montane monsoon forest; 21°24.161'N, 101°36.412'E; 791 m; 16.VI.2013; Q. Zhao and Z. Chen leg. (SYNU-379). Paratypes. 1♀: same data as for holotype (SYNU-380); 3♂1♀: Xiaolongha, Xishuangbanna Biodiversity Conservation Corridor, Qidaoban, valley forest; 21°24.808'N, 101°37.874'E; 711 m; 18.VI.2013; Q. Zhao and Z. Chen leg. (SYNU-381-384).

Diagnosis.

The new species is similar to I. mangun sp. nov. and I. xiaolongha sp. nov. by the lamella-like membrane of the male palp and short dorsal abdominal scutum, but can be distinguished by the large cockscomb-shaped sclerotized process (Fig. 1H-J) of the male cheliceral fang (vs the unmodified cheliceral fang (Fig. 4H, I) in I. mangun sp. nov. and the tongue-shaped sclerotized process (Fig. 17H-J) in I. xiaolongha sp. nov.), the broad rectangular-shaped retrolateral lobe of the bulb (Fig. 2F) (vs the leaf-shaped lobe (Figs 5F, 18F) in I. mangun sp. nov. and I. xiaolongha sp. nov.). The female differs from I. mangun sp. nov. and I. xiaolongha sp. nov. by the large bowl-shaped atrium (Fig. 3H) (vs small rectangular-shaped atrium (Fig. 6F) in I. mangun sp. nov. and small bell-shaped atrium (Fig. 19H) in I. xiaolongha sp. nov.).

Description.

Male (holotype). Body: habitus as in Fig. 1A-C; body length 1.64. Carapace: 0.88 long, 0.65 wide; yellow, with egg-shaped patches behind eyes, surface of elevated portion of pars cephalica smooth, sides finely reticulate, lateral margin straight, smooth (Fig. 1D, E). Clypeus: height about 2/3 of ALE diameter (Fig. 1G). Eyes: see Fig. 1D, G. Sternum: pale orange (Fig. 1F). Mouthparts: chelicerae, endites and labium orange; chelicerae straight, base of fangs with large cockscomb-shaped sclerotized process, fang groove with a few small denticles (Figs 1H-J, 22A, B); anteromedian tip of endites with one strong, tooth-like projection (Fig. 1F). Abdomen: 0.76 long, 0.44 wide; dorsal scutum well sclerotized, pale orange, covering 1/3 of the abdomen width and approximately 2/3 of the abdomen length, fused to epigastric scutum; epigastric and postgastric scute well sclerotized, pale orange, fused, postgastric scutum covering about 2/3 of the abdomen length (Fig. 1A-C). Legs: pale orange, femur I with 2 prolateral spines, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Leg II spination similar to leg I except femur with only 1 prolateral spine. Legs III and IV spineless. Palp: trochanter with ventral projection, cymbium brown; bulb with 2 ventral protuberances, one large and another very small, distal end of bulb elongated, with numerous lamella-like membranes, retrolateral lobe broad, rectangular-shaped (Figs 2, 20A-C).

Female (paratype, SYNU-380). Same as male except as noted. Body: habitus as in Fig. 3A-C; body length 1.76. Carapace: 0.72 long, 0.67 wide. Mouthparts: chelicerae and endites unmodified. Abdomen: 1.05 long, 0.67 wide; dorsal scutum covering 1/3 of the abdomen length, about 1/4 of the abdomen width. Epigastric area: postgastric scutum with strongly sclerotized structure in the middle (Fig. 3H). Endogyne: from the middle of the slightly thickened margin of the postgastric scutum runs a dark, simple winding tube, ending in a large bowl-shaped atrium (Fig. 23A, B).

Etymology.

The specific name is a Latin adjective and refers to the large cockscomb-shaped sclerotized process of the cheliceral fang.

Distribution.

Known only from the localities of the type series.