Genera Heteroinys and Neotoma. 235 



grey. Tail sharply bicolor, black above, white below and 

 on the sides ; well covered with hairs, but the scales showing 

 through. Ears very large, laid forward they reach in front 

 of the anterior canthus of the eye ; their minute hairs reddish 

 brown. 



Skull strongly built, its frontal profile convex ; supra- 

 orbital ridges strongly marked ; anterior palatine foramina 

 barely reaching backward to the level of the anterior root of 

 ^. Teeth small ; their structure as usual. 



Dimensions of the type (an old male in spirit) : — 



Head and body 180 raillim., tail 165 ; hind foot, without 

 claws, 33'7 ; ear from notch 29. 



Skull: basal length 41 "6, greatest breadth 24*7; nasal 

 length 18*4 ; interorbital breadth 6 ; interparietal, length 5, 

 breadth 11 ; palate, length 2o*l ; length of palatine foramina 

 9'8, upper molar series 8"4. 



Idab. San Diego, California. Coll. Prof. Eigenmann. 



Neotoma lepida^ sp. n. 



Size very small, smaller than in any known species. 

 Colour soft ashy grey, washed with pale fawn, the general 

 tone not unlike that of specimens of N. arizonce ; hairs 

 of chest and inguinal region pure white, those of belly 

 grey basally. Ears large, their minute hairs whitish. Hands 

 and feet pure white. Tail very thickly haired, so much so 

 as to be intermediate between that of the round-tailed and 

 the bushy-tailed species, the scales entirely hidden by the 

 hairs ; its colour mixed brownish fawn above, white below. 



Skull small and delicate ; frontal profile flattened ; supra- 

 orbital edges square, scarcely ridged ; palatine foramina as in 

 N. macrotis; molars small. 



Dimensions of the type (a skin, fully adult) : — 



Head and body (probably stretched) 180 millira., tail (c.) 

 100, hind foot 27-2, ear 25. 



Skull: lambda to nasal tip 34*5; greatest breadth 21'2 ; 

 nasal length 14-6; interorbital breadth 5*4; palate, length 20 : 

 palatine foramen 8*2 ; upper molar series 7'5. 



Unh. Utah. 



This interesting wood-rat had been put down nsN.cinei-ea, 

 but its far smaller size and less bushy tail will readily distin- 

 guish it Irom that species. 



