Crotalus pusillus Klauber
Crotalus pusillus Klauber, Bull. Zool. Soc. San Diego, 26:34, August 8, 1952.—Tancítaro, Michoacán, México.
Acuaro de las Lleguas (2); Carapan; Cerro Tancítaro (16); Dos Aguas (12).
Aside from the type series of Crotalus pusillus from Cerro Tancítaro and one specimen from Carapan referred to the species by Klauber (1952:38), there are fourteen specimens from the Sierra de Coalcomán. These specimens (UMMZ 112566-7, 118591-9, 118601, 121512-3) are like Crotalus pusillus from Cerro Tancítaro in having the prefrontals paired, a black proximal rattle, and the underside of the tail black. The prefrontals are bordered posteriorly by one scale in two specimens, by two scales in three specimens, and by three scales in the other nine. The snakes from the Sierra de Coalcomán have 40 to 46 (42) dorsal body blotches. Ten males have 150-158 (154.4) ventrals and 29-33 (31.0) caudals; two females have 157 and 160 ventrals, and 25 and 27 caudals. The largest specimen is a male having a body length of 545 mm. and a tail length of 63 mm. The only noticeable difference between the specimens from the Sierra de Coalcomán and the topotypic series is that the latter have fewer dorsal blotches; the range of variation is 33 to 46 (39.8).
Most specimens of this species have a grayish brown dorsum and dark brown dorsal blotches. Two specimens from Dos Aguas (UMMZ 118596 and 118599) are pale brown above and have indistinct blotches.
One specimen from Dos Aguas regurgitated a large Gerrhonotus imbricatus imbricatus; of two others from the same locality, one regurgitated a Sceloporus bulleri and an Eptesicus fuscus. The latter specimen was collected at the entrance of a small cave, where it probably had captured the bat.
In the Cordillera Volcánica Crotalus pusillus has been obtained in pine-oak forest at elevations between 1550 and 1800 meters. In the Sierra de Coalcomán two specimens were taken in pine forest at an elevation of 2300 meters; ten other were found beneath rocks and logs in pine-oak forest at an elevation of 2100 meters.
Crotalus triseriatus aquilus Klauber
Crotalus triseriatus aquilus Klauber, Bull. Zool. Soc. San Diego, 26:24, August 8, 1952.—Alvarez, San Luis Potosí, México.
Morelia (10); Tacícuaro (2).