46 BULLETIN 18 7, UNITED STATES NATIONAL MUSEUM 



Genus DENDROPHIDION Fitzinger 



DendropMdion Fitzingejr, Systema reptilium, 1843, p. 26. — Sttjaet, Occ. Pap. 

 Mus. Zool. Univ. Michigan, No. 236, 1932, pp. 5-6. 



Genotype. — Herpetodryas dendrophis Schlegel. 

 Range. — Southern Mexico to northern South America. 

 Species. — One in Mexico, three others in Central America ; the num- 

 ber in South America is uncertain. 



DENDROPHIDION VINITOR Smith 



fDendrophidion dendrophis Bocoubt, Le Naturaliste, ser. 2, No. 47, 1889, pp. 4&-48, 



figs. 1-4. 

 Dendrophidium dendrophis Duces, La Naturaleza, ser. 2, vol. 2, 1892, pp. 100-101, 



pi. 5 (in color). 

 Dendrophidion vinitor Smith, Proc. Biol. Soc. Washington, vol. 54, 1941, pp. 73-76 ; 



Proc. U. S. Nat. Mus., vol. 93, 1943, pp. 415-416, fig. 13. 



Type.— U.S.N.M. No. 110662. 



Tyjje locality. — Piedras Negras, Peten, Guatemala. 



Range. — Humid Atlantic slopes from central Veracruz and Oaxaca 

 to Panama; known at present only from foothill regions (known in 

 Mexico only from three localities : Motzorongo, Veracruz; La Gloria, 

 Oaxaca; and Teapa, Tabasco). 



Genus DIADOPHIS Baird and Girard 



Diadophis Baird and Gibard, Catalogue of North American reptiles, 1853, p. 112. — 

 Blanchaed, Bull. Chicago Acad. Sci., vol. 7, No. 1, 1942, pp. 1-444, figs. 1-26, 

 tables 1-17, maps 1^ (monograph). 



Genotype. — Coluber pimctatus Linnaeus. 



Range. — Central Veracruz and Michoacan northward on the plateau 

 into the United States. 



Species. — Fifteen species and subspecies, five of which occur in 

 Mexico.^^ 



KEY TO MEXICAN FORMS OF DIADOPHIS^ 



1. Light ventral color extending onto first row of dorsal scales at least 



anteriorly 2 



Light ventral color not extending onto first row of dorsal scales ; ventrals 

 164 to 183 in males, 201 to 207 in females ; collar present dugesii 



'^ AMaies occipitalis Giinther (Catalogue of the snakes in the British Museum, 1858, 

 p. 29), described on the basis of two cotypes, one from Mexico and one from United States, 

 is considered by Blanchard (op ■cit.) as a synonym of the eastern United States race, 

 /). p. punctatiis. The name is restricted by Boulenger (Catalogue of the snakes in the 

 British Museum, vol. 2, 1894, p. 207) to the cotype from "Mexico," which he selects as 

 "type." The locality data apparently are in error, however, for no Diadophis is known 

 from Mexico with 15 scale rows and 149 ventrals ; Blanchard believes the type probably 

 came from South Carolina or Georgia. 



"Adapted from Blanchard, op. cit. 



