Thaiderces thamphadaengensis Li & Chang sp. nov. Figs 1I, 2K, 23, 24, 28D, 29

Types.

Holotype: ♂ (IZCAS), Thailand, Mae Hong Muang Province, Muang District, Mok Jumpae Subdistrict, Tham PhaDaeng Cave, 19°25.395'N, 97°59.057'E, 293 m, 21.XI.2016, Zhao H., Li Y., Chen Z. Paratype: 1♀ (IZCAS), same data as holotype.

Etymology.

The species name is an adjective referring to the type locality.

Diagnosis.

Thaiderces thamphadaengensis sp. nov. can be distinguished from other species of the genus by the distinct long, flat and tapered embolic stalk (vs. embolic stalk not flat and tapered in other congeners); females can be distinguished by two pairs of spermathecae, lateral pair with short stalks, median pair circular (vs. one pair of similar spermathecae, tubular or twisted spermathecae in other congeners).

Description.

Male (holotype). Total length 1.30; carapace 0.60 long, 0.59 wide; abdomen 0.70 long, 0.44 wide. Carapace round and brown, with three longitudinal dark brown bands, lateral bands three times wider than the median band (Fig. 23C). Chelicerae brown (Fig. 28D). Clypeus dark brown medially and light brown laterally. Endites brown. Labium dark brown. Sternum with dark brown pattern, delimiting an inverted triangle medially. Abdomen elongated, dorsum with indistinct brown pattern, posterior with brown stripes, anteroventrally with dark brown semi-circle, posterior with pair of pale yellow vertical dotted lines laterally. Legs uniformly brown; measurements: I missing, II 4.45 (1.25, 0.20, 1.25, 1.00, 0.75), III 3.70 (1.00, 0.20, 1.01, 0.94, 0.55), IV 5.66 (1.40, 0.25, 1.63, 1.50, 0.88). Palp (Fig. 24 A–D): femur 5 times longer than patella; patella not swollen, tibia 2/3 the length of femur; cymbium with dark brown spots anteriorly, 1/3 the length of femur; bulb pale yellow, spatulate, with elongated, tapered embolic stalk, embolic stalk half the width of bulb, embolus short, arises distally from bulb (Fig. 24A).

Female (paratype). General features and coloration similar to that of male (Fig. 23D, E). Measurements: total length 1.60; carapace 0.50 long, 0.62 wide; abdomen 1.10 long, 0.70 wide. Leg measurements: I missing, II 3.99 (1.09, 0.25, 1.12, 0.90, 0.63), III 3.38 (0.94, 0.20, 0.87, 0.87, 0.50), IV 4.63 (1.09, 0.16, 1.38, 1.25, 0.75). Endogyne: two pairs of spermathecae, lateral pair with short stalks bearing a globose distal part, head two times longer and wider than stalk, median pair circular, ratio of the interdistance of lateral pair to interdistance of median pair 1: 1.50 (Fig. 23A).

Distribution.

Known only from the type locality (Fig. 29).