Occasional Papers of the Museum of Zoology 7 



aa'. Usually a single anterior temporal; scale formula generally 17-19-17, 

 rarely higher than 19-17. 



bb'. Red areas continuous across the belly. 



L. elapsoidcs elapsoides (Holbrook). 

 (North Carolina and Kentucky, south to New Orleans and through- 

 out Florida.) 



bb^. Red not continuous across the belly, but restricted to black-bordered 

 dorsal saddles that extend upon the ventrals. 



L. elapsoidcs virginiana Blanchard. 

 (Northern North Carolina to Delaware.) 



aa^ Usually two anterior temporals; scale formula very rarely lower than 19- 

 21-19-17. 



cc'. Whitish annuli or cross-bands 18 to 23; pattern of body prac- 

 tically in rings L. triangultim amaura (Cope). 



(Lower Mississippi Valley.) 



cc*. Whitish cross-bands 23 to 60; pattern of dorsal saddles or 

 blotches of red or brown. 



dd'. Infralabials 8 or 9, rarely 10; tail less than 16 per cent of 

 total length; often a dark band from eye to angle of mouth. 



ee'. Dorsal saddles 35 to 60, reaching down to the fifth or 

 third row of scales; often two rows of lateral alternating 

 blotches; a dark band on posterior portion of prefrontals; 

 a black-bordered light band from the eye to the angle of 

 the mouth; usually a Y-shaped light spot on the back 

 of the head. . L. triangulum Iriangulum (Lacepede). 

 (Eastern United States and southern Canada.) 



ee^ Dorsal saddles 23 to 35, extending down to the third 

 row of scales, or lower; only one series of alternating 

 spots; head markings of triangulum only partially or not 

 at all developed. . . . L. triangulum sys pita (Cope). 

 (Southern Indiana to Minnesota, south to central 

 Arkansas and west to central Kansas.) 



dd^ Infralabials 10; tail more than .16 of total length; a dark 



blotch behind the eye L. mexicana (Garman) . 



(San Luis Potosi, Mexico.) 



p^. Whitish cross-bands on body and tail more than 40; top of head black, 



snout uniformly white L. pyrrhomclaena (Cope). 



(Utah, Arizona, western New Mexico, and northern Mexico.) 



