A New Species of Snake in the Genus Atractus (Colubridae: Xenodontinae) from Northeastern Brazil

-A new species of Atractus is described from the Atlantic Forest of the states of Sergipe and Alagoas, northeastern Brazil. It can be distinguished from other Atractus by the combination of a long loreal, temporal formula 1 + 2, 7 supralabials, dorsal scales in 15 rows, and a dorsal color pattern of small transverse brown bands on a reddish ground color. Comparisons are made with all other Atractus species with 15 dorsal scale rows, but the lack of data precludes the finding of its precise relationships. RESUMO. -Uma nova especie de Atractus e descrita para a regiao de Floresta Atlantica dos estados do Sergipe e Alagoas, do nordeste do Brasil. Pode ser distinguida das demais especies de Atractus pela combinacao de uma loreal longa, 7 supralabiais, formula temporal 1 + 2, 15 fileiras de escamas dorsais em volta do corpo, e um padrao de coloraqao dorsal composto por finas faixas transversais castanho sobre uma cor de fundo avermelhada. Comparacoes sao feitas com todas as demais especies de Atractus com 15 fileiras de escamas dorsais, mas a falta de dados impede uma definikao prescisa de suas relaoqes. l erpetology, Vol. 29, No. 3, p. 416-419, 1995 i t 1995 Society for the Study of Amph bians and Reptiles ecies of Snake in the Genus Atractus Herpetologically, the northeastern portion of Brazil (an area roughly defined by the states north of 15? S and east of 46? W) is poorly known. Recently, there have been several studies of the herpetofauna of interior regions of this area (e.g., Vanzolini, 1974, 1976; Vanzolini et al., 1980; Rodrigues, 1991). However, no comprehensive herpetological study has ever been made of the coastal region. Such a study is most urgent owing the rapid ongoing destruction of the Atlantic Forest. Although most Atlantic Forest snakes i all , the northeastern portion of a roughly defined by the states a d east of 46? W) is p orly known. e e ave been several studies of the a of interior regions of this area (e.g., have wide distributions, this pattern is not true of the species in the genus Atractus, most of hich have restricted ranges and are therefore more sensitive to human disturbance. Most species of Atractus are poorly represented in museum collections and, despite the efforts of Savag (1960) and Hoogmoed (1980), who dealt with small geographic regions, a complete revision is still needed. While examining A. reticulatus, I found some misidentified specimens that repr ent a new taxon, which I propose to call: 416 This content downloaded from 207.46. 13.149 on Wed, 28 Sep 2016 04:13:01 UTC All use subject to http://about.jstor. org/terms NEW ATRACTUS FROM BRAZIL FIG. 1. Dorsal pattern of Atractus potschi. Atractus potschi sp. n. (Figs. 1 and 2) Holotype. -Instituto Butantan, IB 48438, an adult male from Maceio, State of Alagoas, Brazil, collected on 19 July 1985, by Adilton Jose do Santos. Paratypes. -Museu de Zoologia da Universidade de Sao Paulo, MZUSP 7196, an adult female, MZUSP 7001,7195,7197, adult males, from Salgado, State of Sergipe, Brazil, collected on 29 April 1978 by I.M. Freire; MZUSP 7275,7276, 7278, 7280, 7281, males, and MZUSP 7277 and 7279, females, from Salgado, State of Sergipe, Brazil, collected between September and November 1978 by I.M. Freire. Diagnosis. -An Atractus distinguished from all others by the combination of a long loreal, temporal formula 1 + 2, seven supralabials, 7-8 maxillary teeth, 15 scale rows around the body and a dorsal color pattern of small transverse brown bands on a reddish ground color (refer to Table 1 for diagnostic features to other Atractus species that likely occur at the same area). Description of the Holotype. -An adult male, snout-to-vent length (SVL) 255 mm; tail length 35 mm (13.7% of SVL); head length 9.6 mm (3.76% of SVL) from rostral to posterior tip of mandible, head width 7.0 mm (72.9% of head length) at broadest point; distance across eye 1.1 mm; snout length 3.0 mm (2.72 times distance across eye); head barely distinct from the body, rostral about 1.6 times broader than high; internasals as broad as long; prefrontals about 1.3 times broader than long; frontal as broad as FIG. 2. Holotype of Atractus potschi, IB 48438. Dorsal, lateral and ventral aspects of the head. l ng; parietals about 1.5 times longer than wide; nasal divided; loreal about 4.1 times longer than high; eye small, pupil round; postocular 2; temporals 1 + 2; supralabials 7, 3 and 4 contacting orbit; mental 1.7 times wider than long, separated from chinshields by the first pair of infralabials; infralabials 7, 1 to 4 contacting chinshields; anterior chinshields about twice as long as wide; posterior chinshields absent. Maxillary teeth 7. Dorsal scales in 15-15-15 rows, scales smooth without apical pits. Ventrals 147; anal single; paired subcaudals 35. Hemipenis extending to the level of the seventh subcaudal scale, bilobed, bifurcation occurring at the level of the sixth subcaudal. Variation (12 Specimens). -Maximum SVL 351 mm in females and 312 mm in males; tail length 8.6-11.7% (X = 9.9, s2 = 1.33, N = 3) of SVL in females and 8.8-14.7% (X = 13.0, s2 = 2.10, N = 9) in males. In MZUSP 7276, there are 8 supralabials on the right side, with 4 and 5 con5mm 417 This content downloaded from 207.46. 13.149 on Wed, 28 Sep 2016 04:13:01 UTC All use subject to http://about.jstor. org/terms