A revision of the spider genus Phaeacius ( Araneae : Salticidae) F. R. Wanless Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction Phaeacius Simon 1900 is a small genus of oriental salticids comprised of five known species three of which are described here as new. They are characterized by the presence of a long slender secondary conductor in males (Fig. 5C) and a specialized patch of spatulate setae, of unknown function, on the underside of coxae IV in females. It is unfortunate that the biology is unknown as it would be of interest to compare the behaviour of these salticids with that of Portia Karsch, a closely related genus of detritus mimics, some species of which build webs of their own as an aid to capture prey or invade the webs of other spiders and feed on the occupants (Wanless, 1978&). In spite of their large size (total length 7'5 to 11 -5 mm) Phaeacius species are rare in museum collections and in the majority of cases only the types were available for study. The measurements were made in the manner described by Wanless (19780), but for the leg spination the system adopted is that used by Platnick and Shadab (1975). Genus PHAEACIUS Simon Phaeacius Simon, 1900:32. Type species Phaeacius fimbriatus Simon, by original designation. Simon, 1901:406-408. Waterhouse, 1902:280. Petrunkevitch, 1928:182. Roewer, 1954:935. Bonnet, 1958:3493. Cocalus: Thorell, 1892 : 353 [in part]. DEFINITION. Medium to large spiders ranging from about 7'5 to 1 1*5 mm in length. Sexual dimorphism not marked. Most species hirsute, with similar colour patterns consisting of white marginal carapace bands and leaf-like abdominal markings composed of setae which are easily rubbed; abdominal markings may also include granules of subcutaneous guanin (Fig. 9A) possibly an artifact of preservation. Carapace: of medium height, longer than broad, widest between coxae II-III, lateral margins with distinct membraneous border (arrowed in Fig. 5E); fovea long and sulciform, situated just behind posterior median eyes; eye region finely punctate and weakly iridescent (evident only in rubbed specimens). Eyes: set on well developed tubercles, with black surrounds that are normally covered in hairs; arranged in three transverse rows comprised of anterior medians and anterior laterals, posterior medians, and posterior laterals; anteriors densely fringed in hairs, more or less subcontiguous with apices slightly procurved in frontal view; anterior medians largest, anterior laterals more than half diameter of anterior medians; posterior medians relatively large, positioned slightly closer and on or slightly inside optical axis of anterior laterals, posterior laterals almost as large as anterior laterals, set slightly closer together and well inside lateral margins of carapace; quadrangle formed by posterior median and posterior lateral eyes broader than long and widest posteriorly; entire quadrangle (measured from base of anterior medians to posterior margin of posterior laterals) occupying between 37 and 44 per cent of carapace length. Clypeus: between 25 and 36 per cent of diameter of anterior median eyes; clothed in hairs; ventrally a sometimes rather broad segmental membrane bearing a median subtriangular sclerite. Chelicerae: robust; more or less parallel, slightly inclined anteriorly; basal region usually clothed in hairs, short in central area, long on lateral Bull. Br. Mus. nat. Hist. (Zool.) 41(4): 1 99-2 1 2 Issued 26 November 1 98 1 199
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