Apostenus Westring, 1851

Bosselaers, Jan, 2009, Studies in Liocranidae (Araneae): redescriptions and transfers in Apostenus Westring and Brachyanillus Simon, as well as description of a new genus, Zootaxa 2141, pp. 37-55 : 39

Apostenus Westring, 1851

Apostenus Westring, 1851: 46 .

Type species: Apostenus fuscus Westring, 1851

Diagnosis. Apostenus can be distinguished from all other liocranid genera by the presence of 4–5 ve spine pairs on ti I and II, a male abdomen with a ventral mat of short setae, a male palp with a prolateral hookshaped embolus facing a retrolaterally implanted median apophysis, an epigyne with a median septum and a vulva with oval spermathecae 1 with a longitudinal long axis.

Description. Small (2–4) spiders. Carapace yellow to brown, with faint striae and darker margin, sparsely covered by thin hairs. A short but distinct fovea in posterior third. Chilum absent. PLB thin, isolated. Eyes in two transverse rows of four, both procurved in fr view and recurved in do view. All eyes subequal, except AME whose diameter is only 1/2–1/3 of others. ME in both rows further removed from each other than from laterals. MOQ posterior width up to twice anterior width. Clypeus vertical, about 1–2 times diameter of AME. Chelicerae coloured as carapace, vertical, tapering towards fang base, without cheliceral boss, sparsely covered with conspicuous, long straight hairs. Promarginal cheliceral rim with three teeth, retromarginal rim with two teeth. Sternum shield shaped, smooth, not rebordered, yellow to ochre. No PCT nor ICS. Labium trapezoidal to subrectangular, with thickened anterior rim, wider than long. Maxillae parallel-sided, 2–3 times as long as labium, no ventral depression or apical hair tuft, with a distinct but small serrula. Legs unicolorous ochre to brown or faintly ringed, no trochanter notch, patellar indentation wide. Leg formula 4123. Femora with 2–3 do spines. Ti I with 5, ti II with 4–5, mt I and II with 3 ve spine pairs. Tarsi with two pectinate claws with four teeth. No claw tufts but one pair of large tenent hairs ( Forster 1970: 18; Ubick & Vetter 2005) present ( Fig. 1 D ). No vt preening brush on mt III or IV, no feathery hairs. Abdomen oval, with some curved grey setae at anterior rim, ochre to grey-brown, unicolorous or bearing a row of paler chevrons. Male abdomen with a ventral mat of short setae ( Ubick & Vetter 2005; Wunderlich 2004, 2008). ALS conical with short apical segment, PLS subcylindrical, widely spaced. Male PMS slender, female PMS stout and subtriangular, with 2–3 large cylindrical gland spigots.

Male palp with a single, pointed RTA and an oval tegulum with a hook shaped pl embolus facing a rl MA. Epigyne weakly to heavily sclerotised, with a median septum which is narrow or lozenge-shaped in some species and posteriorly widened and anchor- or spade-shaped in others. Vulva with oval ST1 with a longitudinally oriented long axis and glandular structures ( Grimm 1986). No ST2, CO anterior.

Figures

FIGURE 1 A – E. Apostenus humilis. F – G. Apostenus ochraceus. A, B, male holotype. A, left male palp, rl view; B, left male palp, ve view; C, epigyne; D, leg II, tarsal tip; E, vulva, ve; F. vulva, ve.; G, epigyne. Scale bars: 0.1.