Psechrus elachys Bayer 2012, sp. nov.
Creators: name: Bayer, Steffen
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Psechridae
Psechrus
Psechrus elachys

description: Psechrus elachys sp. nov.
Figs 17a–g, 82f, 83d, 84i, 87i, 90i
Type material: Holotype ♀ (SB 861), THAILAND: Satun Province: Thale Ban National Park, N 06°42', E 100°10', 350–400 m, lowland rain forest; M. Andersen, O. Martin and N. Scharff leg. 20.X.1991; ZMUC 4538. Paratype ♂ (SB 862), with same data as for holotype; ZMUC 4538.
Etymology. The specific name refers to the small body size of the holotype female (Ancient Greek “elachys” means “little, small, short”); term (adjective) in apposition.
Diagnosis (see also diagnosis for singaporensis -group above). In males embolus (E) in ventral view narrower than in P. singaporensis, erected steep and its tip more clearly pointed (Figs 17b–c) than in P. singaporensis. Embolus base (EB) protruding beyond upper retrolateral margin of tegulum (T) (Fig. 17b). E ventrally with creaselike structure (Figs 17b–c). Females similar to P. singaporensis in having a rather simple median septum (MS) and medium sized copulatory ducts (CD) with spermathecal heads (SH) located upon distal section —thus the section close to spermatheca— of CD (Figs 15e–f,h–i, 17d–e). Distinguished by the small copulatory opening (CO) pointing anteriorly (Figs 17d, 87i), leading to a different course of CD (Fig. 17f cf. Fig. 15g). CD a bit narrower and shorter (Fig. 17e, 90i) than in singaporensis.
Description. Male:
Body and eye measurements. Carapace length 5.1, carapace width 3.3, anterior width of carapace 1.8, opisthosoma length 6.0, opisthosoma width 2.2. Eyes: AME 0.29, ALE 0.35, PME 0.35, PLE 0.33, AME–AME 0.15, AME–ALE 0.06, PME–PME 0.22, PME–PLE 0.22, AME–PME 0.38, ALE–PLE 0.34, clypeus height at AME 0.49, clypeus height at ALE 0.38.
Cheliceral furrow with three promarginal and four retromarginal teeth.
Measurements of palp and legs. Leg formula: 1423. Palp: 5.8 [2.1, 1.0, 0.8, 1.9]; Legs: I 56.0 [14.9, 2.3, 14.9, 16.2, 7.7], II 40.9 [11.4, 1.9, 10.3, 11.5, 5.8], III 26.8 [7.6, 1.5, 6.6, 7.3, 3.8], IV 43.7 [12.1, 1.7, 10.5, 13.1, 6.3].
Spination. Palp: 131, 110 (both very small), 1101 (all very small); legs: femur I 656, II 666, III–IV 555; patella I–IV 000; tibia I 3038, II 3036, III–IV 3136; metatarsus I–IV 3035.
Palpal femur modified with rounded ventral bulge (Fig. 17g). MC-I and MT-I: present, but just as apical row.
Copulatory organ (see also diagnosis and general description for singaporensis -group). Conductor (C) shape similar to P. singaporensis, but C arising subdistally at prolateral section of T (Figs 17a–b). Palpal tibia (Fig. 17a–c) very similar to P. singaporensis.
Female (both legs II are missing):
Body and eye measurements. Carapace length 5.1, carapace width 3.6, anterior width of carapace 2.1, opisthosoma length 8.5, opisthosoma width 3.3. Eyes: AME 0.32, ALE 0.38, PME 0.38, PLE 0.38, AME–AME 0.21, AME–ALE 0.06, PME–PME 0.23, PME–PLE 0.31, AME–PME 0.45, ALE–PLE 0.38, clypeus height at AME 0.81, clypeus height at ALE 0.62.
Cheliceral furrow with three promarginal and four retromarginal teeth.
Measurements of palp and legs. Leg formula:? Palp: 6.5 [2.2, 0.9, 1.3, 2.1]; Legs: I 42.5 [11.6, 2.2, 11.8, 11.1, 5.8], III 22.0 [6.7, 1.4, 5.4, 5.6, 2.9], IV 33.7 [9.8, 1.7, 8.7, 8.6, 4.9].
Palpal claw with 14 teeth.
Spination. Palp: 131, 110, 1101, 1014; legs: femur I 656, III 555, IV 545; patella I–IV 000; tibia I 3038, III–IV 3136; metatarsus I&III 3035, IV 3036.
Copulatory organ (see also diagnosis and general description of singaporensis -group). MS more or less trapezoid (Fig. 17d). Slit sense organs and epigynal muscle sigilla outside epigynal field. CD with winding for 1/4 length at most until reaching receptaculum (Fig. 17e), ca. 1.5x longer than diameter of receptaculum.
Colouration of male and female (see also description for singaporensis -group and Psechrus). Median bands on carapace serrated (Fig. 82f). Width of lateral bands ca. 1.4x diameter of PME and serrated.
Distribution. Thailand (Fig. 99).
description: Published as part of Bayer, Steffen, 2012, The lace-sheet-weavers — a long story (Araneae: Psechridae: Psechrus), pp. 1-170 in Zootaxa 3379 (1) on pages 41-43, DOI: 10.11646/zootaxa.3379.1.1, http://zenodo.org/record/6039832