492 8. TE1ID& 



{ . Ground color of throat and chest whitish, yel- 

 lowish, grayish, or slaty, not chiefly black, 

 g. Markings on sides of head not well-defined, 



almost obsolete. 



h. Throat usually suffused with slate or gray. 

 Western States, northern Sonora, north- 

 eastern Lower California. 



C. t. tessellatus.- p. 508. 



h*. Throat not suffused with slate or gray, 

 an ill-defined middorsal light line. Cen- 

 tral Lower California. 



C. bartolomas. p. 523. 



g*. Markings on sides of head very distinct and 

 well-defined; throat not (sometimes slight- 

 ly) suffused with gray or slate, 

 hh. Median subcaudal scales not nearly all 



with spots. 



i. Spots on throat few and small; central 

 gular and collar scales smaller. Cali- 

 fornia. 



C. t. mundus. p. 516. 



i". Spots on throat numerous and large, often 

 forming irregular transverse bands; cen- 

 tral gular and collar scales larger. South- 

 ern California and northwestern Lower 

 California. 



C. t. stejnegeri. p. 519. 



hh*. Median subcaudal scales nearly all with 

 large black spots. Cerros and Natividad 

 islands. 



C. multiscutatus. p. 526. 



f. Ground color of throat or chest often black or 

 blackish. 



