622 Bulletin American Museum of Natural History [Vol. XLVI 



San Ltjcan Species Occurring in the San Diegan Fauna 

 (a). As Identical Species 



Batrachoseps attenuatus Plestiodon skiltonianus 



Hyla regilla Coluber lateralis 



Uta microscutata Rhinocheilus lecontei 



Verticaria hyperythra schmidti Hypsiglena ochrorhynchus ochrorhynchus 



(b). As Related Species 



San Lucan San Diegan 



Sceloporus licki Sceloporus occidentalis bi-seriatus 



Gerrhonotus multi-carinatus Gerrhonotus scincicauda webbii 



Lichanura trivirgata Lichanura roseofusca 



Lampropeltis getulus conjuncta Lampropeltis getulus boylii 



Lampropeltis California nitida Lampropeltis calif ornix calif ornix 



As there are no important additions to be made to the faunae of the 

 Revilla Gigedo Islands and islands off the Pacific coast of Lower Cali- 

 fornia, with the exception of Cedros Island, they may be omitted from 

 the present resume. Van Denburgh and Slevin (1914) have given a com- 

 plete account of these insular fauna?. 



The fauna of Cedros at present known consists of eleven species : 



Hyla regilla Verticaria hyperythra beldingi 



Crotaphylus wislizenii *Cnemidophorus multisndatus 



*Uta concinna *Cnemidophorus labialis 

 Sceloporus rufidorsum Siagonodon humilis 



*Phrynosoma cerroense Crotalus exsul 



*Phrynosoma schmidti 



The five species starred are peculiar to the island. Hyla regilla, Scelo- 

 porus rufidorsum, the Verticaria, and Crotalus exsul are San Diegan forms 

 reaching Cedros. It is not impossible that they are cut off by a consider- 

 able gap from their nearest mainland occurrence, as the Crotaphytus 

 and Siagonodon apparently represent an invasion of the desert forms. 

 The relations of the peculiar forms are not fully established, but it seems 

 certain that Uta concinna and Cnemidophorus multiscutatus are most 

 closely allied to San Diegan forms, while the remaining three are repre- 

 sentatives of the adjacent Vizcaino Desert fauna. 



The islands of the Gulf of California appear to fall simply enough 

 into two groups, those nearest the peninsula having a non-Mexican and 

 strictly Lower Calif ornian fauna, while those nearer the mainland have a 

 fauna derived from Mexico. 



