Pholcus duan Yao & Li sp. nov.

Figs 3–4

Type material. Holotype: male (Ar29662), Kuha Sawan Cave (7°37.205′N, 100°04.905′E, elevation 15 m), Mueang District, Rattalung, Thailand, 27 October 2015, Q. Zhao, G. Zhou and Z. Chen leg. Paratypes: 2 females (Ar 29663–29664), same data as holotype.

Etymology. The specific name is a Chinese pinyin word for short (duǎn), in reference to the short procursus; adjective.

Diagnosis. The species can be easily distinguished from all known congeners in the P. bidentatus species group by the very short and simple procursus (Figs 3 A–D), by the T-shaped appendix (Fig. 4 C) and by the large, proximally sclerotized embolus (Fig. 4 C).

Description. Male (holotype): Total length 5.31 (5.58 with clypeus), carapace 1.60 long, 1.80 wide, opisthosoma 3.76 long, 1.13 wide. Leg I missing, leg II: 37.74 (9.94 + 0.75 + 9.55 + 15.71 + 1.79), leg III: 26.72 (7.69 + 0.75 + 6.60 + 10.38 + 1.30), leg IV: 34.08 (9.62 + 0.80 + 8.46 + 13.53 + 1.67). Distance PME-PME 0.66; diameter PME 0.11; distance PME-ALE 0.04; distance AME-AME 0.06; diameter AME 0.06. Sternum wider than long (1.10/0.90). Habitus as in Figs 4 E–F. Carapace yellowish, with brown marks medially; ocular area brownish, with a brown median band; sternum brown. Legs brownish, distal parts of femur and tibiae, and proximal part of metatarsi yellowish, darker rings absent. Opisthosoma yellowish, with brown spots posteriorly. Ocular area elevated; each eye triad on top of a long, laterally directed eye-stalk. Thoracic furrow absent. Chelicerae as in Fig. 3 D, with a pair of proximo-lateral apophyses, distal apophyses absent. Pedipalps as in Figs 3 A–B; trochanter with a short ventral apophysis; femur with a dorsal apophysis proximally (arrow in Fig. 3 B) and a distinct ventral hump; procursus short and simple; bulbal apophyses as in Fig. 4 C; uncus small; appendix T-shaped in prolateral view; embolus large, sclerotized proximally. Legs with short vertical setae on tibiae, metatarsi and tarsi; without spines and curved setae.

Female: Similar to male, habitus as in Figs 4 G–H. Total length 5.86 (6.28 with clypeus), carapace 1.50 long, 1.78 wide, opisthosoma 4.36 long, 1.92 wide; Leg I: 52.11 (12.43 + 0.74 + 12.82 + 24.09 + 2.03); tibia I L/d: 73. Distance PME-PME 0.26; diameter PME 0.12; distance PME-ALE 0.05; distance AME-AME 0.05; diameter AME 0.06. Sternum wider than long (1.09/0.94). Ocular area without eye-stalks. Epigynum (Fig. 4 A) with a broad knob. Vulva (Fig. 4 B) with a sclerotized anterior arch and two rounded pore plates. Retrolateral trichobothrium of tibia I at 6%; legs with short vertical setae on tibiae, metatarsi and tarsi; without spines and curved setae; tarsus I with 7 distinct pseudosegments.

Variation: Tibia I in another female paratype: 13.52.

Distribution. Thailand (Rattalung, type locality; Fig. 21).

Natural History. The species was found in the aphotic zone inside the cave.