1018 The American Naturalist. [December, 
To these must be added the species already enumerated as 
common to the Diegan and Lower Californian districts, and 
the following list of species which occur also in the Chihua- 
huan district : 
Crotaphytus wislizenii B. & G. Lichanura roseofusca Cope. 
Callisaurus draconoides Bly. Orotalus adamanteus atrox B. 
Uta stansburiana B. & G. & G. . 
Sceloporus biseriatus Hallow. 
The following species are common to the Diegan and Pacific 
districts : 
SERPENTES: 
Charina bottz Blv. 
Zamenis lateralis Hallow. 
Zamenis tæniatus Hallow.* 
Pityophis catenifer Blv. 
BATRACHIA: 
Diemyctylus torosus Esch. 
Hyla regilla B. & G.* 
SAURIA: 
Phrynosoma blainvillii 
Ophibolus getulus boylii B. 
& G.* 
Gray. Eutænia elegans couchii 
Gerrhonotus multicarinatus enn. 
Blv.* Eutenia infernalis infernalis 
Gerrhonotus burnettii Gray. Blv 
Eumeces skiltonianus B. & 
Crotalus confluentus lucifer 
B. & G. 
These species are then characteristic of the Western subre- 
gion as a whole, except those marked with a star, which occur 
elsewhere. | : 
The Pacific district is especially characterized by certain 
genera and species of Batrachia. No certainly known genus 
of scaled reptiles, and a limited number of species and subspe- 
cies are peculiar to it. Conspicuous among these are the species 
of Eutzenia, which display great variety, while they are but 
sparsely represented in the Diegan district. The peculiar spe 
cies are as follows: 
