Another Cryptic Associate of the Lizard Sceloporus formosus in Guerrero, Mexico

Sceloporus adleri, a new species founded on 41 specimens, is related to the geographically adjacent species S. formosus, and is presumably limited to the Sierra Madre del Sur, Guerrero, Mexico. This Sierra appears to possess sufficient biotic endemism to justify recognition as a distinctive biotic province. Among specimens secured in Guerrero, Mexico, by Kraig Adler and his group during the winter of 1969, are 12 of a remarkably colorful species of Sceloporus cryptically related to S. formosus Wiegmann. Several other specimens of the same species had been secured by Adler earlier in the same area, and an additional series was secured for us in 1972 by David M. Dennis. We name this population Sceloporus adleri sp. nov. Holotype.-University of Michigan Museum of Zoology (UMMZ) 131689, a male, taken at Asoleadero, Guerrero, Mexico, 2520 m, on 17 December 1969, by Kraig Adler, David M. Dennis and David H. Snyder. Field no. MN 4466. Paratypes.-Forty, all from Guerrero, including UMMZ 126282 (5, field nos. IJ 1522-6), Cerro Teotepec (ca. 125 km by road W Xochipala), 3300-3400 m., 10 August 1964, Theodore J. Cohn and Jean Cohn; UMMZ 130134 (6, field nos. GH 9264-7, 9270-1), between Puerto Chico and Asoleadero, 2550-2600 m, 13-14 June 1964, Kraig Adler, Guy G. Musser and James H. Brown; Colorado University Museum (CUM) 50651-3, 5 km E Escalerillo, 2460 m, 20 December 1972, David M. Dennis, David H. Snyder, Mike Silvey, Don F. Harker; Field Museum of Natural History 191335-6, U.S. National Museum (USNM) 193236, University of Illinois Museum of Natural History 93532, all topoparatypes, 16 December 1969; Kansas University Museum of Natural History (KUMNH) 143612, CUM 46010, Museum of Comparative Zoology (MCZ) 129779, Brigham Young Univ. Mus. 40188, American Museum of Natural History (AMNH) 108211, California Academy of Science 133089, all topoparatypes, 17 December 1969; British Museum (Natural History) 1971.1856, ca. 3km (by road) E Puerto Gallo, 2740 m, 19 December 1969; CUM 50636-50, 2415 m; all topoparatypes, 19 December 1972, David M. Dennis, David H. Snyder, Mike Silvey, Don F. Harker. Twenty (USNM, KUMNH, CUM 46010, 50639-42, 50644, 50646-7, 50649, 50652, MCZ, AMNH, UMMZ field nos. 1522-3, 1526, 9264-5, 9270) are males; all others (20) are females. Collectors are Kraig Adler, David M. Dennis and David H. Snyder, unless otherwise noted. Definition.-A Sceloporus of the formosus group, distinguished from other members by the following combination of characters: mean dorsal scales 38.4; mean ventral scales 49.4; mean scales around midbody 43.7; mean femoral pores 13.3; mean scales between femoral pore series 12.8; median frontonasal in contact with lateral frontonasals; supraoculars generally not distinctly wider than long and generally not in contact with median head scales; scales on posterior surface of thigh relatively small; an incomplete, posteriorly light-bordered black nuchal collar; a pair of dorsolateral light stripes (obscure in large males); tan to dark brown dorsally in *Present address: Museum of Natural History, University of Kansas, Lawrence, Kansas 66045, USA.