CHECKLIST OF THE SNAKES OF MEXICO 101 



America; one of the latter is comprised of two subspecies. Two 

 species are recorded from Mexico, and another possibly occurs there. 



KEY TO MEXICAN SPECIES OF OPHEODRYS 



1. Dorsal scales keeled, in 17 rows aestivus 



Dorsal scales smooth, in 15 rows ; supralabials usually G mayae 



OPHEODRYS AESTIVUS (Linnaeus) 



Coluier aestivus Linnaeus, Systema naturae, ed. 12, vol. 1, 176G, p. 387. 

 Opheodrys aestivus Cope, Proc. Acad. Nat. Sci. Philadelphia, 1800, p. 580. — 



Schmidt and Davis, Field booli of snakes, 1941, pp. 118-120, fig. 27, pi. 12. 

 Cyclophis aestivus Cope, Ann. Rep. U. S. Nat. Mus., 1898 (1900), pp. 784-787, fig. 



170. 



Type. — Unknown. 



Type locality. — Carolina. 



Range. — Southwestern Connecticut to Florida, west to north- 

 eastern New Mexico, south through the Gulf States and to extreme 

 northeastern Tamaulipas, north in the Mississippi Valley to southern 

 Ohio, central Indiana, central Missouri, and southeastern Kansas 

 (known in Mexico only from Matamoros and La Vegonia, Tatnauli- 

 pas, and Santiago, Nuevo Leon), 



OPHEODRYS MAYAE (Gaige) 



Eurppholis mayae Gaige, Carnegie Inst. Washington Publ. No. 457, 1936, pp. 



300-301. 

 Opheodrys mayae Schmidt and Neckek, Herpetologica, vol. 1, 1936, p. 64. — 



Gkobman, Misc. Publ. Mus. Zool. Univ. Michigan, No. 50, 1941, p. 10. 



Type.— Univ. Mich. Mus. Zool. No. 73082. 

 7'ype locality. — Dzitas, Yucatan. 



Range. — The northern portion of the Yucatan Peninsula (known 

 from several localities in Yucatan). . 



Genus OXYBELIS Wagler 



Oxybelis Waglee, Natiirliches System der Amphibien, 1830, p. 183. 



Genotype. — Dryinus aeneus Wagler. 



Range. — Extreme southwestern United States and both coasts of 

 Mexico southward to northern Argentina. 



Species. — Six are tentatively recognized, and four may occur in 

 Mexico. 



KEY TO MEXICAN SPECIES OF OXYBELIS 



1. Head strongly tapering, rather broad posteriorly ; usually 10 supralabials, 

 the last 2 with nearly equally long labial borders ; scales rather markedly 



keeled ; green fulgidus 



Head much less tapering, not much broader posteriorly than anteriorly ; 

 usually eight or nine supralabials, the last much the longest ; scales 

 not or feebly keeled; brownish 2 



