380 



BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



Remarks. — The above description, based on specimens from the 

 western part of San Diego County, near the Pacific Ocean, in south- 

 ern California, reflects the extreme characters of the dark littoral race 

 of Onychomys torridus which Mr. Rhoads has mimed ramona; but 

 Rhoads's description was based on the larger and paler inland form, 

 taken in the San Bernardino Valley, California — a region whence he 

 and Dr. Merriam have described several other intergrades between the 

 races of the Colorado Desert and Pacific coast regions, which should 

 not have received names, unless it can be shown that these interme- 

 diates arc identical with the forms of the great interior valley of Cali- 

 fornia, an area of sufficient importance to merit recognition as a mam- 

 mal differentiation tract; but, even in this case, the selection of the 

 Sun Bernardino Valley instead of the San Joaquin Valley as the type 

 locality is unfortunate. In the case of Onychomys torridus ramona, 

 the type, fortunately, bears a closer resemblance to the coast form 

 than to that of the Colorado Desert, and the name ramona can, there- 

 fore, be applied to the Pacific coast form. 



Measurement of 13 specimens of Onychomys torridus ramona. 



" In the collection of the American Museum of Natural History, New York. 



'' Mammae, I pairs I Holzner). 



• Collected by F. X. Holzner. 



'' I.' hi me hv Mr. Samuel X. Rhoads; measurements by Mr. Herron. 



''Collected by Chas. H. Marsh. 

 I 'I'M"' 



