44 Mr. O. Thomas on new Mammals from 



be a matter of much interest to see whether it merges insen- 

 sibly into the Californian bat, or is replaced abruptly by the 

 latter in the northern parts of the peninsula. In the former 

 case it would probably have to be considered as an indepen- 

 dent southern modification of subsp. typicus^ and in the latter, 

 like Dasypterus ega xanthinus and Natalus stramineus, as a 

 direct invader of the tropical part of the peninsula by one of 

 the Central-American forms. 



Peromyscus eva^ sp. n. 



A small rufous species with a long tail, in general appear- 

 ance almost more like a Reithrodontomys or a small Oryzomys 

 than a Peromyscus. 



Size rather small. Fur close and straight. General colour 

 sandy rufous, the head and fore back more greyish, the rump 

 more rufous. Back lined with brown, but not conspicuously 

 so ; sides gradually becoming clearer rufous, which attains its 

 brightest at its junction with the white of the belly. Under 

 surface white, the slaty bases of the hairs showing through. 

 Face greyish, with but slight tinge of rufous ; a narrow dark 

 line round the eye. Ears very large, very thinly haired, pale 

 brownish, not conspicuously darker in colour than the head. 

 Upper surface of hands and feet silvery whitish, not snowy 

 white, the ankles rather duskier. Tail very long, much 

 longer than head and body, very thinly haired, not pencilled, 

 dull brown above, little or not lighter below, never conspicu- 

 ously bicolor. 



Skull with a broad low brain-case; supraorbital edges 

 square, but not beaded. Palatal foramina reaching just to 

 the level of the front edge of m}. 



Dimensions of the type (an adult male, measured in the 

 tlesh) :— 



Head and body 88 millim. ; tail 108*; hind foot 21; 

 ear 17. 



Skull : basal length 20'3 ; basilar lengtli 18*8 ; greatest 

 breadth 12*8; nasals, length 9'6 ; interorbital breadth 4; 

 interparietal 3'7 X 9 ; breadth of brain-case on squamosals 

 11*7; palate length from henselion 10; diastema Q'Q ; pala- 

 tal foramina 4*8 X 2*1 ; upper molar series '6'Q. 



Bah. San Jos^ del Cabo, Lower California. Coll. 

 D. Coolidge. 



Type collected July 29, 1896. Original number 525. 

 Thirty-nine specimens examined, of which twenty-three are 

 from Santa Anita, tive from Sierra Laguna, and eleven from 

 San Jose del Cabo. 



* Eange up to 128. 



