A revision of the spider genus Sobasina (Araneae : Salticidae) F. R. Wanless Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction The genus Sobasina Simon, 1897 was formerly known only from a single specimen of the type-species Sobasina amoenula Simon from the Santa Cruz Islands in the southwest Pacific Ocean. Several new localities reported by Berland (1938) from the New Hebrides are not accepted here as all of his specimens have been misidentified. In this present paper the genus is redefined and five new species are described. The measurements were made in the manner described by Wanless (1977/8), but for the leg spination, the system adopted is that used by Platnick & Shadab (1975). Sobasina is comprised of small ant-like spiders whose distribution appears to be restricted to the chain of Pacific Islands extending from the Bismarck Archipelago in the north to the New Hebrides in the south. The genus is not represented in the New Guinea or New Caledonia collec-tions of the British Museum (Natural History). The distribution pattern (Fig. 1) suggests that allopatric speciation may have occurred as some islands have endemic species ; however, there are very few records and no firm conclusions can be reached at the present time. The species are evidently all closely related and appear to form a good monophyletic genus. Most species can be readily distinguished by the form of the carapace, sculpturing, and the pre-sence or absence of ventral tibial fringes on legs I. The genitalia are less useful in this respect as they are small, pale and rather similar. The biology is unknown but two species have been found in litter and the small size of the others suggests that they too may also live in litter, a habitat often overlooked by the early collectors. Genus SOBASINA Simon Sobasina Simon, 1897 : 275. Type-species Sobasina amoenula Simon, by monotypy. Simon 1901 : 512, 513. Petrunkevitch, 1928 : 183. Roewer, 1954 : 957. Bonnet, 1958 : 4090. DEFINITION. Ant-like spiders ranging from about 2-5 to 3-8 mm in length. Sexes alike in general body form but males sometimes with dorsal and ventral abdominal scuta. Colour markings sub-dued; not hirsute but carapace usually with marginal white haired patch above coxae I. Carapace: shape variable; sculpturing variable, usually a combination of papillae and punctures (PI. la, b, d, e); fovea lacking. Eyes: anterior row contiguous with apices strongly recurved; middle row about midway between anterior lateral and posterior lateral eyes or sometimes nearer to anterior laterals; posterior row wider than anterior row; quadrangle length between 49 and 57 per cent of carapace length. Clypeus: low, more or less vertical. Chelicerae: small to medium; more or less subvertical; promargin with 2 teeth, retromargin with a biscuspid tooth (i.e. in chelicerae examined which do not include all species described here). Maxillae: parallel or slightly conver-gent. Labium: subtriangular. Sternum: elongate scutiform with scalloped margins. Pedicel: long rather stalk-like; anterior dorsal and ventral segments well developed, posterior segment vestigial (PI. Ic). Abdomen: shape variable; constriction and/or scuta sometimes present; spinnerets subequal in length, arranged in two rows, posteriors and medians slender and dorsal to robust anteriors; trachea branched, arising from transverse slit just in front of spinnerets (Fig. 4F); colulus represented by two minute setae. Legs: slender but coxae and trochanters I elongate; femora I dorsoventrally enlarged and slightly compressed laterally with tibiae I sometimes slightly enlarged and fringed below with stiff hairs; formula 1432 or 1423; spination: dorsal and lateral Bull. Br. Mus. not. Hist. (Zool.) 33 (4): 231-296 Issued 27 April 1978 245
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