Mesiotelus Simon, 1897

Fu, Jianying, Zhang, Feng & Zhu, Mingsheng, 2008, Redescription of a little-known spider species, Mesiotelus lubricus (Simon, 1880) (Aranei: Liocranidae) from China, Arthropoda Selecta 17 (3), pp. 169-173 : 171

Mesiotelus Simon, 1897

Mesiotelus Simon, 1897:143 ; Song, Zhu & Chen, 2001: 304.

Type species: Cheiracanthium tenuissimus L. Koch, 1866 , by original designation.

DIAGNOSIS. The presence of a long male palp (especially long tibia and patella) distinguishes the genus Mesiotelus from other liocranid genera. The genus Mesiotelus presumably has close affinities with the Palearctic genus Liocranum and the Nearctic genus Hesperocranum on the basis of potentially derived genitalic characters: male palpal tibia with a prolateral lobe and epigynum with a similar conformation, including an anterior hood and posterior spermathecal sacs and ducts [ Ubick & Platnick, 1991].

Mesiotelus can be distinguished from Hesperocranum by: tibiae and metatarsi I, II with interspersed typical spines and relatively few pairs of ventral bristles ( Fig. 7 ), while the latter without spine and with numerous pairs of ventral bristles on tibiae and metatarsi I—III; epigynum with single hood anteriorly, while the latter with a bipartite hood; also Mesiotelus can be further distinguished from Hesperocranum by having recumbent, feathery leg setae, and the male with prognathous chelicerae.

Mesiotelus is also very similar to the Liocranum , but can be distinguished from the latter by: metatarsi I, II with only one pair of long ventral spines, while the latter has two or three pairs of long ventral spines; epigynum with a single small, half-moon shaped hood anteriorly, while the latter often has a large and variously shaped hood; also Mesiotelus can be further distinguished from Liocranum by having fewer pairs of ventral bristles on tibiae and metatarsi I, II.

Figures

Figs 1 - 7. Mesiotelus lubricus: 1 — male body, dorsal view; 2 — male endites, labium and sternum, ventral view; 3 — male left chelicera, posterior view; 4 — female left femur IV, dorsal view, showing spines; 5 — female left femur I, dorsal view, showing spines; 6 — female left tibia and metatarsus IV, ventral view, showing spines; 7 — female left tibia, metatarsus and tarsus I, ventral view, showing spines; TI — tibia; M — metatarsus. Scale bars: 1 — 2 mm; 2 — 1 mm; 3 — 0.5 mm; 4 - 7 — 0.1 mm.