The Amphibians and Reptiles of Michoacán, México

by William Edward Duellman

Thamnophis subcarinata subcarinata, Smith, Herpetologica, 5:63, May 31, 1949.

Thamnophis eques eques, Smith, Copeia, no. 2:139, June 8, 1951.

Jiquilpan; Lago de Cuitzeo; Lago de Pátzcuaro (17); Pátzcuaro (5); Tangancícuaro; Tupátaro (2); Undameo; Zacapu.

Although this snake has been collected in open pine-oak forest and in oak-bunch grass associations, it seems to reach its greatest abundance in marshes on the Mexican Plateau at elevations of 1550 to 2300 meters.

Thamnophis melanogaster canescens Smith

Thamnophis melanogaster canescens Smith, Zoologica, 27:117, October 23, 1942.—Chapala, Jalisco, México.

Lago de Cuitzeo (5); Lago de Pátzcuaro; Pátzcuaro; Tacícuaro; Tangamandapio (2).

This species of garter snake seems to be most abundant in the marshes adjacent to the lakes on the Mexican Plateau in Michoacán and Jalisco. At these elevations (1550 to 2200 meters) it often is found in association with Thamnophis eques eques and sometimes with Thamnophis dorsalis cyclides. On June 11, 1958, individuals of this species were found in a hyacinth-choked marsh at Tangamandapio at night.

One specimen from Tangamandapio (UMMZ 119414) had, in life, a dark chocolate brown dorsum, reddish brown sides, and cream-colored belly, chin, and labials. There were no longitudinal dorsal stripes.