A revision of the Neotropical spider genus Ancylometes Bertkau (Araneae : Pisauridae)

The spider genus Ancylometes Bertkau, 1880 is revised. A. vulpes Beakau, 18 80, type species of the genus, is considered a junior subjective synonym of Dolomedes concolor Perty, 1833. Both types are lost and we redescribe the species based on specimens similar to those found at the type locality of A . vulpes. Spiders of the genus are large nocturnal ground-living hunting sp iders with a strong affinity in most species, to water bodies within their tropical environment. Those species hunt also on small vertebrates like fro gs, tadpoles and fishes. All species show slight sexual dimorphism in colou r and body-to-leg-size relations. Females carry brown egg-sacs in chelicera e and build a nursery web. The genus is morphologically diagnosed by the pr esence of ventral spines on tarsi III and IV in both sexes and by their gen ital characters: filiform embolus with a basal membranous lobe, wing-like c onductor and hammerlike median apophysis in males; female epigyne consistin g of two broad lateral plates and a central plate in form of a bike saddle with its nose pointing posteriorly. Ten valid species are recognized and de scribed, five of them are new: Ancylometes japura, A. jau, A. riparius from Amazonas, A. terrenus from Acre, Amazonas and Mate Grosso and A. pantanal from Matto Grosso do Sul, all from Brazil. The female of A. amazonicus is d escribed for the first time and the female of A. hewitsoni for the first ti me based on an adult specimen. Ancylometes vulpes Bertkau, Ctenus argentinu s Holmberg, Ancylometes bolivianus Tullgren, Lycoctenus bahiensis Strand, L ycoctenus selenkae Strand, Lycoctenus paraguayensis Strand, Cupiennius arge ntinus Petrunkevitch, Ctenus paulensis Mello-Leitao, Cupiennius diplocellat us Mello-Leitao, Ctenus originalis Mello-Leitao, Ctenus iophorus Mello-Leit ao, Corinoctenus anomalostomus Mello-Leitao, Ctenus infelix (Mello-Leitao, Ctenus metatarsalis Mello-Leitao, Phoneutria niveobarbata Mello-Leitao and Corinoctenus greenwayi Carcavallo & Martinet are newly synonymized with A. concolor (Perty). Ctenus fuscus Walckenaer, Ctenus giganteus Taczanowski, C tenus bimaculatus Taczanowski, Leptoctenus tenkatei Hasselt, Lycoctenus bru nneus Pickard-Cambridge, Lycoctenus gigas Pickard-Cambridge, Lycoctenus dem erarensis Pickard-Cambridge, Lycoctenus saraensis Strand, Lycoctenus paraen sis Strand, Ancylometes pindareensis Mello-Leitao, Ancylometes pindareannus Mello-Leitao, Ctenus juruensis Mello-Leitao, Ctenus striolatus Mello-Leita o, Ctenus xerophilus Mello-Leitao and Lycoctenus titanus Caporiacco are new ly synonymized with A. rufus (Walckenaer). Lycoctenus palustris Pickard-Cam bridge, Ancylometes orinocensis Simon, Lycoctenus venezuelensis Strand, Lyc octenus caracasensis Strand and Ctenus nasutus Kraus are newly synonymized with A. bogotensis (Keyserling). A. valentinei Petrunkevitch, 1925 from Pan ama is a Cupiennius (new combination) and considered a senior synonym of C. panamensis Lachmuth et al., 1985. The geographical distribution is Neotrop ical, with one northern widespread species (A. bogotensis) reaching Central America, one widespread species of the Amazon reaching the Sao Paulo coast al area and one widespread species of central Brazil reaching Argentina. Fr om the Amazon region six rarely collected species are described and one spe cies was recently collected in the Pantanal of Brazil.