GEOGRAPHIC VARIATION IN THE POCKET GOPHER, CRATOGEOMYS CASTANOPS, IN COAHUILA, MÉXICO

Sinopsis de GEOGRAPHIC VARIATION IN THE POCKET GOPHER, CRATOGEOMYS CASTANOPS, IN COAHUILA, MÉXICO

The plateau pocket gopher, Cratogeomys castanops, inhabits open lands from southeastern Colorado southward onto the Mexican Plateau as far south as southern San Luis Potosí and southeastern Zacatecas and southeastward to the Coastal Plain of northern Tamaulipas. This species occurs at elevations from as low as 26 feet at Matamoras in Tamaulipas to as high as 8700 feet in valleys of south-eastern Coahuila. In 1934, Nelson and Goldman (Proc. Biol. Soc. Washington, 47:135-154, June 13, 1934) revised the genus Cratogeomys and decided that six subspecies of C. castanops occurred in Coahuila. In the present account, we describe four previously unknown subspecies from Coahuila, exclude from the state two others recorded from there by Nelson and Goldman, and show that three others named previously from adjacent Mexican states do occur in Coahuila. This makes eleven subspecies now known from that state. From Coahuila Nelson and Goldman had 35 study specimens of C. castanops from seven localities and we have had 234 specimens from 63 localities. Consequently we have been able to define with greater certainty, than formerly was possible, the geographic distribution of C. castanops in this Mexican state and similarly analyze more completely the geographic variation.