SONORA— LOWER CALIFORNIA REPTILES 33 



46. Crotalus atrox 



47. Kinostemon sonoriense 



48. Gopherus agassizii 



49. Dermochelys schlegelii 



Lower California seems to comprise four chief areas of 

 reptile distribution. These are: First, the Cape Region, 

 north to about La Paz, in which there is practically an in- 

 sular fauna which includes representatives of tropical, 

 Lower Sonoran, and Upper Sonoran zones; second, the cen- 

 tral portion of the peninsula, chiefly Lower Sonoran; third, 

 the northwestern portion of the peninsula, a part of the San 

 Diegan Fauna of the Upper Sonoran Zone; fourth, the 

 northeastern portion of the peninsula, which is a southward 

 extension of the Colorado Desert and is Lower Sonoran. 



The reptiles of Lower California, not including the 

 islands of the west coast and of the Gulf of California, are: 



1. Phyllodactylus tuberculosus 



2. Phyllodactylus unctus 



3. Coleonyx variegatus 



4. Ctenosaura hemilopha 



5. Dipsosaurus dorsalis dorsalis 



6. Dipsosaurus dorsalis lucasensis 



7. Sauromalus ater 



8. Sauromalus interbrachialis 



9. Crotaphytus collaris baileyi 



10. Crotaphytus wislizenii 



1 1 . Uma notata 



12. Callisaurus crinitus 



13. Callisaurus draconoides draconoides 



14. Callisaurus draconoides carmenensis 



1 5. Callisaurus ventralis ventralis 



16. Holbrookia maculata approximans ? 



17. Uta thalassina 



