Dos Aguas (3).
The three specimens comprising the type series of the species were found beneath logs and in a stump in pine-oak forest at an elevation of 2100 meters. A discussion of the variation in these specimens and of probable relationships of the species was given by Duellman (1959). Floyd Downs spent several days at Dos Aguas in July, 1960; although he found ten specimens of Geophis incomptus, no further specimens of G. nigrocinctus were obtained.
Geophis petersi Boulenger
Geophis petersii Boulenger, Catalogue Snakes... British Museum, 2:321, September 23, 1894.—Mexico City. Type locality restricted to Pátzcuaro, Michoacán, México, by Smith and Taylor (1950a:335).
Cherán; Coalcomán; Morelia; Pátzcuaro (6).
This seems to be the most widespread species of Geophis in Michoacán. It has been found at elevations between 950 and 2350 meters, chiefly in pine or pine-oak forest. Boulenger (1894:321) described Geophis petersi from a specimen stated to be from Mexico City, a locality which probably is in error. The only localities from which the species is definitely known are those listed in this account.
Three males and five females from the Mexican Plateau and the Cordillera Volcánica have respectively 140-144 (141.7) and 143-151 (146.0) ventrals and 39-41 (40.0) and 29-35 (33.2) caudals. All have dorsal scales in 15 rows, 1 postocular, no anterior temporal, and a relatively small triangular supraocular. The specimen from Coalcomán (UMMZ 104698) was referred to Geophis nasalis by Peters (1954:22). This specimen is abnormal in several characters; in five places there is a fusion and separation of the vertebral and paravertebral scale rows, producing a change from 17 to 15 rows of dorsal scales. Fusion of the three rows takes place at the level of the 8th, 41st, 47th, 54th, and 65th ventrals. Furthermore, there is a small secondary postocular on each side of the head. In other characters the specimen is like G. petersi; the resemblances to that species are greater than to G. nasalis, which has been recorded from Guatemala and southern Chiapas.
Geophis tarascae Hartweg
Geophis tarascae Hartweg, Occ. Pap. Mus. Zool. Univ. Michigan, 601:1, May 4, 1959.—Uruapan, Michoacán, México.
Uruapan (3).