CKOCODILIANS, LIZARDS, AND SNAKES. 1225 



V. THE WESTERN SUBREGION. 



This subregion presents two distinct modifications, a northern and a 

 southern. The boundary between the two has not yet l)een dehned; 

 it represents the demarkation between the greater iiuinidity of the 

 north and the arid conditions of the south. The name J)ief/<m has 

 been given by Mr. Van Deuburgh to the southern region; to the 

 northern 1 propose to restrict the name Pacijic, which 1 formerly used 

 for the entire subregion, which had been previously named the Western 

 by Baird. The Pacific district extends farther south along the Sierra 

 Nevada than in the San Joaquin Valley. Some of the forms of the 

 Diegan district extend north to the latitude of San Francisco, but the 

 majority of the species are restricted to more southern latitudes. TIow 

 far the Diegan district extends on the Lower Californian Peninsula is 

 uncertain. The separation from the Chihuahuan district is also unde- 

 termined, and the species of both districts mingle in some degree on 

 their borders. 



Species peculiar to the Diegan district are the following: 



BATRACHIA. 



Rufo Golumbiensis halopliila Baird and Girard. 



SAURIA. 



Uta repens Van Denburgh. 



Utamearnsii Stejneger. 



Sceloporus orcuttii Stejneger. 



ISceloporus vandenhergianus Cope. 



Phrynosoma cerroense Stejneger. 



Anota goodei Stejneger. 



Xantusia vigilis Baird. 



Xantusia river siana Cope. 



Xantusia picta Cope. 



Zablepsis henshavii Stejneger. 



Anuchopsis gilhertii Van Denburgh. 



Verticaria sericea Van J)enburgh. 



Cnemidophorus tessellatns multiscutatus Cope. 



Gnemidophorus tessellatns rubidus Cope. 



Anniella pulchra Gray. 



SERPENTES. 



TAchamira ormittii Stejneger. 



Diadophis amabilis amabilis Baird and Girard. 



Crotalus ruber Cope. 

 To these must be added the species already enumerated as common 

 to the Diegan and Lower California districts, and the following list of 

 species which occur also in the Chihuahuan district : 



Crotapliytus irislizcnii Baird and Girard. 



Gallisanrus draconoides Blainville. 



