937 Accepted by P. Jäger: 31 Mar. 2005; published: 12 Apr. 2005 1 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2005 Magnolia Press Zootaxa 937: 1–12 (2005) www.mapress.com/zootaxa/ Four new species and new records for the spider genus Synotaxus Simon, 1895 (Araneae: Synotaxidae) from Brazil ADALBERTO J. SANTOS 1 & CRISTINA A. RHEIMS 1,2 1 Laboratório de Artrópodes, Instituto Butantan. Av. Vital Brasil 1500, CEP 05503-900, São Paulo, SP, Brazil; oxyopes@yahoo.com 2 Pós-graduação em Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil; cris.rheims@butantan.gov.br Abstract Four new species of Synotaxus Simon are described and illustrated based on material from northern and northeastern Brazil: S. brescoviti n. sp., S. bonaldoi n. sp., S. siolii n. sp. and S. itabaiana n. sp. New records are presented for S. longicaudatus (Keyserling), S. monoceros (Caporiacco) and S. waiwai Agnarsson. A map with all species records included is provided. Key words: Taxonomy, zoogeography, distribution range, Neotropical region Introduction The spider genus Synotaxus was described by Simon (1895) to include two species of small, Argyrodes-like Neotropical spiders: S. turbinatus Simon and S. uncatus Simon. The genus was originally placed in Theridiidae (Simon 1895, Levi & Levi 1962, Exline & Levi 1965). Forster et al. (1990), however, suggested that Synotaxus is related to several genera of small spiders of Austral temperate distribution, including Physoglenes Simon, a genus with a problematic history of familial placements. This group was hypothesized as sister to Theridiidae+Nesticidae, and received the name Synotaxidae, based on Simon’s (1895) tribal-group Synotaxeae. The monophyly of Synotaxidae, as well as its phylogenetic prox- imity to the Theridiidae-Nesticidae clade was later corroborated by Griswold et al. (1998) and Agnarsson (2003, 2004). According to Agnarsson (2003), Synotaxus monophyly is supported by at least 10 morphological and behavioral characters. This genus can be easily recognized, and sepa- rated from similar araneoids, by its characteristics “chicken-wire” shaped web (Eberhard 1977: figs. 1, 3; Eberhard 1995: fig. 1; Agnarsson 2003: fig. 6, 2004: fig. 95A) and by the