GEOGRAPHIC VARIATION AND TAXONOMY OF THE SAND SNAKES, CHILOMENISCUS (SQUAMATA: COLUBRIDAE)

We reevaluated geographic variation and taxonomy in the colubrid genus Chilomeniscus. We used color pattern, head scale morphology, and scale and band counts in an attempt to differentiate the four currently recognized species: the unbanded C. stramineus, banded C. cinctus, and the banded insular forms C. punctatissimus and C. savagei. Because only head scale morphology could be used to discretely diagnose (i.e., no character state overlap) two of the four species, we propose that the current evidence supports the recognition of C. savagei from Isla Cerralvo and two disjunct populations of C. stramineus, one ranging throughout the Baja California peninsula and the other occurring in Arizona, U.S.A., and Sonora and Sinaloa, Mexico. We consider C. cinctus and C. punctatissimus to be junior synonyms of C. stramineus.