136 BULLETIN IS 7, UNITED STATES NATIONAL MUSEUM 



16a. Caudals 66 in a female ; mental in contact with chin shields ; black 



head cap covering 3 scale rows back of parietals yaquia 



Caudals 46 in a female (51 in a male) ; mental separated from chin 

 shields ; black head cap covering 4 scale rows bogerti 



17. Ventrals 134 to 140; nasal divided only below naris planiceps 



Ventrals 164 to 197 ; nasal divided both above and below naris 23 



18. Posterior temporal about as broad as long, scalelike ; and, ventrals 164 



to 185 (195?) bocourti 



Posterior temporal elongate, much longer than broad ; or, if scalelike, 

 ventrals fewer than 164 19 



19. Posterior black border of nuchal collar covering one scale length or 



less 20 



Posterior black border of nuchal collar covering two or three scale 

 lengths 21 



20. Caudals 62 to 69 wilcoxi wilcoxi 



Caudals 51 to 60 wilcoxi rubricata 



21. Caudals 62 or more 22 



Caudals 46 to 49 ( + ) in known specimens miniata 



22. Black of dorsal surface of head not reaching labial border; dorsal and 



ventral surfaces not pink deviatrix 



Black of dorsal surface of head reaching labial border; dorsal and 

 ventral surfaces pink rubra 



23. Ventrals 164 to 175 in males, 169 to 182 in females ; average tail length 



at a total length of 300 mm., 74 in males, 66 in females ; 



darker eiseni eiseni 



Ventrals 175 to 184 in males, 190 to 197 in females ; average tail length 

 at a total length of 300 mm., 69 in males, 59 in females; 

 lighter eiseni transm.ontana 



TANTILLA ATRICEPS (Gunther) 



Eomalocranium atriceps GtiNXHEK, Biologia Centrali-Americana, Rept., 1895, 



pp. 146-147, pi. 52, fig. B. 

 Tantilla atriceps Amaral, Mem. Inst. Butantan, vol. 4, 1929, p. 219. — Smith, 



Zoologica, vol. 27, 1942, p. 34. 



Type.— Brit. Mus. Nat. Hist. 



Type locality. — Nuevo Leon. 



Range. — Centjal San Luis Potosi nortliward to western Oklahoma 

 and central Arizona (recorded in Mexico from near Saltillo and 

 Ciudad Allende, Coahuila; Nuevo Leon; and Kilometer 102 north of 

 San Luis Potosi, San Luis Potosi) . 



TANTILLA BOCOURTI (Gunther) 



Homalocranium 'bocourti Gxjnthek, Biologia Centrali-Americana, Rept., 1895, 

 p. 149. 



Tantilla bocourti Cope, Amer. Nat., vol. 30, 1896, p. 1021. — Tatloe, Trans. Kansas 

 Acad. Sci., vol. 39, 1930 (1937), pp. 335-337, fig. 1; Univ. Kansas Sci. Bull., 

 vol. 20, 1939 (1940), pp. 481-482.— Smith, Zoologica, vol. 27, 1942, pp. 34-35. 



Type.— Brit. Mus. Nat. Hist. 

 Type locality. — Guanajuato. 



Range. — Southern portion of the central Mexican Plateau from 

 Jalisco east to central Veracruz; also the Sierra Maclre del Sur in 



