Psechrus singaporensis, Thorell, 1894

Bayer, Steffen, 2012, The lace-sheet-weavers — a long story (Araneae: Psechridae: Psechrus), Zootaxa 3379 (1), pp. 1-170 : 43

Specimens from singaporensis -group with doubtful identification

Figs 18a–c

Material examined (2 ♂♂, 1 s.a. ♀): MALAYSIA: Terengganu Province: Pulau Perhentian Besar, trail across island , from Teluk Pauh to Teluk Dalam, N 05°53'53'', E 102°44'53'', 110 m, evergreen rain forest; P. Schwendinger leg. at night 05.VI.2008; TPME-08/02 ; 1 ♂ (SB 134), MHNG . MALAYSIA: Pahang Province: Taman-Negara National Park , ca. N 04°40', E 102°28', 200 m, rainforest; P. Nabavi leg. 03.IV.1999; [ex. CJW], |E473/5|; 1 ♂ ( SB 1145 ), 1 s.a. ♀ ( SB 1146 ), SMF .

Description. Male:

Body and eye measurements. Carapace length 7.1, carapace width 5.2, anterior width of carapace 2.7, opisthosoma length 9.4, opisthosoma width 3.5. Eyes: AME 0.42, ALE 0.43, PME 0.43, PLE 0.43, AME–AME 0.21, AME–ALE 0.07, PME–PME 0.26, PME–PLE 0.38, AME–PME 0.43, ALE–PLE 0.41, clypeus height at AME 0.89, clypeus height at ALE 0.67.

Cheliceral furrow with three promarginal and four retromarginal teeth.

Measurements of palp and legs. Leg formula: 1423. Palp: 8.1 [2.9, 1.6, 1.1, 2.5]; Legs: I 87.5 [22.6, 3.5, 23.7, 26.8, 10.9], II 64.1 [16.8, 3.1, 16.5, 19.5, 8.2], III 41.3 [11.6, 2.3, 10.3, 12.0, 5.1], IV 67.0 [18.2, 2.6, 16.7, 20.8, 8.7].

Spination. Palp: 141, 110 (prolateral one very small), 1101 (prolateral and ventral one very small); legs: femur I–II 656, III–IV 555; patella I–IV 000; tibia I 3049, II 3036, III 3134, IV 3136; metatarsus I–III 3035, IV 3036.

Palpal femur modified with rounded ventral bulge like in P. elachys sp. nov. MC-I and MT-I: present, but just as apical row.

Remark: According to the male palp structures ( Figs 18a–c ) these specimens are very similar to P. elachys sp. nov. All features match, except for the following: Embolus with dorsal lobe ( Fig. 18c ). SB 134 from Perhentian solely differs in having a slightly longer tegulum (T) and conductor (C), which arises slightly further retrolateral. This could either mean that the differences to the character features of the palp of the male paratype of P. elachys ( Fig. 17c ) are part of a rather wide range of intraspecific variation in P. elachys sp. nov. On the other hand, it could be that these specimens belong to a new, slightly different species. Further, it cannot be excluded that they are conspecific with P. norops sp. nov., from which only the adult female is known. More Psechrus material from Northern and North-Eastern Malaysia, especially females, is required to help solving this ambiguity.

Figures

FIGURES 17a–g. Psechrus elachys sp. nov., from Thailand, Satun Prov. a–c, g ♂ paratype SB 862. d–f ♀ holotype SB 861. a–c ♂ palp (a prolateral, b ventral, c retrolateral view). g ♂ left palpal femur, retrolateral view. d Epigyne, ventral view. e Vulva, dorsal view. f Schematic course of internal duct system.

FIGURES 18a–c. Psechrus ♂ SB 134 [singaporensis-group] with doubtful identification from Malaysia, Terengganu Prov. a–c ♂ palp (a prolateral, b ventral, c retrolateral view).