University of Michigan 



X'. Yellow rings 25 to 40; black 

 spaces on belly usually shorter 

 than the intervening yellow 

 ones. 



L. triangulum genliUs (Baird 



and Girard). 



(South central Texas to South 



Dakota, west into Utah and 



Arizona.) 



Dorsal whitish bands usually distinctly widened on the 

 first row of scales, or the scale rows anteriorly not 

 more than 17. 



y'. Black practically uniform 

 over the head, except for 

 the snout region, which is 

 more or less lightened, at 

 least on the sides; scale 

 rows anteriorly more than 

 17. 



z'. Whitish annuli or cross- 

 bands 25 to 40; black 

 often strongly encroach- 

 ing upon the red on the 

 mid-dorsal line. 

 L. triangtdiim gent His 

 (Baird and Girard). 



z^. Whitish annuli or cross- 

 bands 18 to 25; black 

 showing not more than 

 a slight tendency to 

 encroach upon the red 

 areas on the mid-dorsal 

 Une. 



L. triangulum atnaura 

 (Cope). 

 (Lower Mississippi 

 VaUey.) 



y'. Black of head practically 

 restricted to posterior por- 

 tion, or to various black- 

 edged light markings. 



