MAMMALS OF THE MEXICAN BOUNDARY. 267 



(livoro'oiit form, more closely related to nh/fipcs than to f/ri.seiis\ from 

 v.'hich latter it may be recognized by the following characters: Size 

 smaller; color paler and less coarsely grizzled; pure AA'hite instead of 

 faintly yellowish on under parts; sides of head paler, with hairs less 

 annnlated with black; feet and tail much blacker; ears narrower and 

 much longer; feet and claws smaller; skull smaller (averaging 68 

 Iw 30 mm. in (uithonyi against TO by 38 in topotypes .of grU-eus), 

 with relatively shorter and broader rostrum and nasals, and very 

 slightly higher audital bulla!." 



P'rom Sciurus griseus nigripes it is only distinguishable by slightly 

 smaller size, paler coloration, and absence of the yellowish-brown 

 suffusion over the back. S. g. nigripes is the darkest, and S. g. an- 

 thonyi the palest form; but the shape of the skull and ears and the 

 color of the feet and tail are very similar. 



I have seen specimens of this form from the oak zone of the 

 Laguna, Cuyamaca, San Jacinto, San Bernardino, and Tejon moun- 

 tains of southern California, its range extending south at least to 

 the Laguna Mountains of Lower California, 50 miles south of 

 Campo, and 70 miles south of the type-locality in San Diego County, 

 California. 



Ilahits and local distrihutioit. — Our specimens were all obtained 

 from the type-locality. It was usually seen in pine and oak trees, 

 often descending to the ground. The young are probably born in 

 IVIay and June, as we obtained a female with her two young on June 

 12, and obtained a very young one June 10. 



a In addition to the facts of the present case, I will say that, accordins to 

 recently-applied standards, no native mammal of the Columbia River Valley is 

 subspecificnlly identical with the same species from any part of Mexico, so far 

 as my comparisons have gone. 



