CHECKLIST OF REPTILES OF MEXICO 79 



DIPSOSAURUS DORSAUS SONORIENSIS Allen 



Dipso-saurus dorsalis sonoriensis Allen, Occ. Pap. Mus. Zool. Univ. Michigan, 

 No. 259, 1933, pp. 4-6. 



Type. — Mus. Zool. Univ. Michigan No. 72121; John Piatt, John 

 Scofield, and Morrow J. Allen collectors. 



Type locality. — Hermosillo, Sonora. 



Range. — Gulf slope of Sonora, except extreme northwestern part, 

 and southward into northern Sinaloa. Reported from Sonora: 5 miles 

 southwest of Hermosillo, Miramar, La Posa, Guaymas, Rancho Costa 

 Rica, Bocoit; Sinaloa: Ahome. 



Genus SAUROMALUS Dumeril 



Sauromalus Dumeril, Arch. Mus. Hist. Nat. Paris, vol. 8, 1856, p. 536. — Shaw, 

 Trans. San Diego Soc. Nat. Hist., vol. 10, 1945, pp. 269-306, map. 



Euphryne Baird, Proc. Acad. Nat. Sol. Philadelphia, vol. 10, 1858, p. 253 (type, 

 Euphryne obesus Baird). 



Genotype. — Sauromalus ater Dumeril. 



Species. — Seven, one with three subspecies. 



Range. — Southern Utah and southern Nevada south through 

 southern CaUfornia, western Sonora and the Gulf slopes of Baja 

 California. 



KEY TO SPECIES OF SAUROMALUS «o 



1. One or more transverse bands dorsally, across body or rump 4 



No transverse body bands present 2 



2. Largest nuchal scales equally as large as or larger than frontal plates. 



hispidus (adult) (p. 80) 

 Largest nuchal scales smaller than frontal plates 3 



3. Dorsal pattern of large, irregular, dark brown or black blotches on a yellowish 



ground color varius (p. 81) 



Dorsal pattern of small, dark brown or black spots on a gray ground color. 



klauberi (p. 80) 



4. Ventral scale rows usually less than 130 5 



Ventral scale rows usually more than 130 6 



5. Dorsal scales in a head length usually less than 20-hispidus (juvenile) (p. 80) 

 Dorsal scales in a head length usually more than 20 slevini (p. 80) 



6. Transverse body bands with light centers and dark brown or black borders 



giving a double-banded effect 9 



Transverse bands unicolor 7 



7. Scales around middle of upper foreleg (humeral scales) usually fewer than 



50 8 



Humeral scales more than 50 obesus obesus (p. 81) 



8. No reddish suffusion on dorsal and ventral areas in adult males; maximum 



adult length averaging somewhat less than in o. tumidus; average scale 



counts lesser obesus townsendi (p. 81) 



More or less brilliant reddish suffusion on dorsal and ventral areas in adult 

 males; maximum adult length averaging more than in o. townsendi; average 

 scale counts greater obesus tumidus (p. 81) 



9. Ventral scale rows 151 or more australis (p. 80) 



Ventral scale rows usually less than 151 ater (p. 80) 



M From Shaw, Trans. San Diego Soc. Nat. Hist., vol. 10, 1945, p. 303. 



