56 BULLETIN 18 7, UNITED STATES NATIONAL MUSEUM 



DRYMARCHON CORAIS RUBIDUS Smith 



Drymarchon corals rubidus Smith, Journ. Washington Acad. Sci., vol. 31, 1941, 

 pp. 474-^76, map fig. 2 (part) . 



Ty^e.— U.S.N.M. No. 46430. 



Type locality. — Rosario, Sinaloa. 



Range. — Southern Sinaloa to the Isthmus of Tehuantepec, on Pacific 

 slopes (recorded from various localities in the states of Colima, Guer- 

 rero, Jalisco, Michoacan, Morelos, Oaxaca, Puebla, Sinaloa, and 

 Sonora). 



DRYMARCHON CORAIS UNICOLOR Smith 



Drymarchon corals miicolor Smith, Journ. Washington Acad. Sci., vol, 31, 1941, 

 pp. 470-472, map fig. 2. 



Type.—U.S.'N.M. No. 110865. 



Type locality. — La Esperanza, near Escuintla, Chiapas. 



Range. — Extreme southern Chiapas to Nicaragua, on Pacific slopes. 



Genus DRYMOBIUS Fitzinger 



DrymoMus Fitzingek, Systema reptilium, 1843, p. 26. — Smith, Proc. U. S. Nat. 

 Mus., vol. 92, 1942, pp. 380-384 (Mexican subspecies of margaritiferus). 



Genotype. — Herpetodryas margaHtiferus Schlegel. 



Range. — Extreme southern Texas and southern Sonora south on 

 both coasts into South America and to southern Peru and northeastern 

 Venezuela. 



Species. — Two species, one with three subspecies, occur in Mexico ; 

 two others occur in Central and South America. 



KEY TO MEXICAN FORMS OF DRYMOBIUS 



1. Adults uniform green above, beUy not marked with darlc color; ventrals 



152-170, caudals 112-125 chloroticus 



Adults with each dorsal scale dark-edged ; ventrals or caudals frequently 

 dark-marked; ventrals 140-159; caudals 101-131 (142?) 2 



2. All or most of posterior edges of subcaudals dark or black 3 



All or most of posterior edges of subcaudals white (subcaudal surface 



unmarked) 4 



3. Anterior edges of median dorsal scales blue (in adult specimens), white 



(faded specimens) or gray (young specimens), color well differentiated 



from a black tip of scale margaritiferus marg'aritiferus 



Anterior edges of median dorsal scales black, color completely surrounding 

 a central light spot margaritiferus fistulosus 



4. Sides of head in temporal region no darker than general tone of dorsal 



surface of nape ; light spots in centers of scales diffuse, gray-brown, 



stippled margaritiferus occidentalis 



An elongate dark (black) area on either side of head behind eye, much 

 darker than general tone of dorsal surface of nape ; light spots in centers 

 of scales well defined, blue or tinged with orange, not or very slightly 

 stippled margaritiferus fistulosus 



