Althepus yizhuang Li & Li sp. n. Figs 18, 19, 20, 22

Types.

Holotype: ♂, Indonesia, Sumatra, West Sumatra Province, Sijunjung, Padang Sibusuk Village, Bukit Ponggang Cave, 00°44.245'S, 100°50.330'E, 278 m a.s.l., 27.V.2014, Z. Yao. Paratypes: 1♂2♀, same data as holotype.

Etymology.

The specific name is derived from the Chinese pinyin 'yi zhuang’, which means ‘sigmoid’, referring to the sigmoid embolus (Figure 18); adjective.

Diagnosis .

Althepus yizhuang Li & Li, sp. n. can be distinguished from all other known species of the genus by the remarkably long and sigmoid embolus as well as by the absence of a conductor in males (Figure 18). Females are distinguished by inconspicuous spermathecae (Figure 19A).

Description.

Male (holotype). Total length 3.13; carapace 1.00 length, 1.14 width; abdomen 1.80 length, 0.94 width. Carapace round, yellow, with triangular brown margins and a narrow, brown median line behind ocular area (Figure 19C). Anterior margin of cephalic region distinctly elevated. Clypeus brown. Cheliceral promargin with two teeth, followed by a lamina, retromargin with two small teeth (Figure 20J), posterior surface of fang with 16 small denticles. Labium brown. Sternum brown, with a triangular yellow patch in the middle. Abdomen elongate, with complex patterns dorsally and ventrally (Figure 19C). Legs brown. Leg measurements: I 24.39 (5.83, 0.43, 6.22, 9.68, 2.23), II 14.81 (3.85, 0.41, 3.85, 5.45, 1.25), III 9.85 (2.81, 0.40, 2.50, 3.20, 0.94), IV 14.47 (4.17, 0.41, 3.91, 4.81, 1.17). Male palp (Figure 18 A–D): tarsus with one hooked spine with tip directed proximally; cymbium slender (Figure 18C); bristles at the top of the cymbial protrusion (Figure 18A) as in A. hongguangi Li & Li, sp. n.; bulb bright yellow, ovate; embolus arising retrolatero-distally from bulb, bright yellow.

Female (one of the paratypes). Total length 3.13; carapace 0.85 length, 0.95 width; abdomen 1.90 length, 1.17 width. Similar to male in colour, general features and body size (Figure 19 D–E). Internal genitalia with inconspicuous spermathecae (Figure 19A). Leg measurements: I missing, II 11.57 (3.00, 0.35, 2.97, 4.00, 1.25), III 8.21 (2.34, 0.36, 2.10, 2.53, 0.88), IV 11.52 (3.20, 0.38, 3.20, 3.60, 1.14).

Variation.

Males: carapace 1.00 length, 1.14-1.25 width; femur I 5.71-5.83 (holotype and paratypes with similar length).

Distribution.

Indonesia. Known only from the type locality (Figure 22).

Natural history.

Collected at a cave entrance at an altitude of 278 m.

Remark.

Althepus yizhuang Li & Li, sp. n., was labelled as "sp. 84" in the analysis of Li and Li (2018).