CHECKLIST OF THE SNAKES OF MEXICO 105 



Type—lj. M. Klauber (San Diego, Calif.) No. 23757. 



Type locality. — Dry Lake, San Diego County, Calif. 



Range. — Southern California, on the eastern or desert side of the 

 mountains, from the Death Valley region south to northeastern Baja 

 California; also central Clark County, Nev., southeast through Mo- 

 have, western Maricopa, and Yuma Counties, Ariz., to extreme north- 

 western Sonora. 



Genus PITUOPHIS Holbrook 



Pituophis Holbrook, North American herpetology, ed. 2, vol. 4, 1842, p. 7. — Stull, 

 U. S. Nat. Mus. Bull. 175, 1940, pp. 1-221, figs. 1-84 (generic revision). 



Epiglottophis Cope, Amer. Nat., vol. 25, 1891, p. 157 [type, Spilotes deppei (Du- 

 meril and Bibron)]. 



Genotype. — Coluber raelanoleucus Daudin. 



Range. — Southern British Columbia, Wisconsin, and New Jersey 

 south through Mexico to central Guatemala. 



Species. — About 13 or 14 species and subspecies exist in the genus. 

 Eight are known from Mexico. 



KEY TO MEXICAN FORMS OF PITUOPHIS " 



1. Two prefrontals ; two labials entering orbit 2 



Four prefrontals ; one labial entering orbit 4 



2. A pair of neck stripes ; all blotches light centered, with well-defined, 



broad, black borders in adults deppei lineaticollis 



No neck stripes; anterior and posterior (or only anterior) blotches solid 

 black, only median blotches brown in adults ; all spots brown in young ; 

 black borders not well-defined when present 3 



3. Anterior interspaces five scales in length or more ; posterior and middle 



blotches brown, dark-edged, anterior blotches black, in adults; body 



spots 21 to 31 deppei jani 



Anterior interspaces four scales in length or less; posterior blotches 

 black, as well as anterior, middle blotches brown, in adults ; body 

 spots 30 to 44 deppei deppei 



4. Rostral at least slightly longer than broad ; sum of ventrals and caudals 



added to number of dorsal spots on body and tail rarely exceeding 



360 5 



Rostral at least slightly bi'oader than long; sum of ventrals and 

 caudals added to number of dorsal spots on body and tail rarely less 

 than 360 6 



5. Rostral slightly longer than broad; all spots on body of about equal 



darkness catenifer affinis 



Rostral nearly twice as long as broad, prominent; anterior spots 

 solid black, posterior and middle spots brown (dark-edged), in 

 adults catenifer sayi 



6. Anterior dorsal spots black or reddish, central spots reddish, and posterior 



spots black; spots usually saddle-shaped and tending to fuse at the 

 sides; anterior spots generally each five or more scales in length; 

 ventrals 236 to 262 vertebralis 



"* Adapted from Stull, op. cit., pp. 24-25. 



