1904.] MOUSE-HARES OF THE GENUS OCHOTOXA. 215 



Przewalski, pi. xxiv. fig. 14) and of 0. dav/rica (ibid. pi. xxv. 

 fig. 2) ; in which it may be noticed that the sides of the foramen 

 in 0. dcmrica diverge at once from their anterior point instead of 

 continuing parallel for the first third of their length, and then 

 tending to approach again before finally diverging, as in the 

 TLifescens gi-oup. 



0. ciirzonice is a pale buff-coloured animal above and rather 

 lighter below. Along the median area of the back the hairs 

 are tipped with black and have a subterminal ring of rufous 

 brown, the extent of the rufous varying in individual specimens. 

 Behind the ears is a clear patch of a rather deeper bufi" than 

 the rest of the body. The ears ai-e of moderate size, clothed on 

 both sides with fairly long whitish hairs. Feet pale bufi". 



The skull of this species is small and narrow. Apai-t from the 

 palatal foramen, of which mention has already been made, the 

 chief point of note is the postorbital process of the zygoma, wliicli 

 is very long and narrow ; the posterior nares ai'e similarly modified. 



Dimensions (approx. from skin). Head and body 170 mm. ; hind 

 foot 28; ear 19. 



Skull. Palatal length 15 mm. ; zygomatic breadth 20 ; lengtli of 

 nasals 12 ; length of molar series 8; interorbital breadth 4. 



HaUtat. The type-locality of this species is the Chumbi Valley 

 in the north of Sikhim, whence it apparently extends westward as 

 far as Kashmir. 



The series of this species at my disposal is so small, that I am 

 unable to give any particulars of its seasonal changes should any 

 occur, but from the specimens before me it appears to be a very 

 uniform species. 



OCHOTOXA MELAXOSTOMA (BUchn.). 



Lagomys melanostomus Blichn. Mamm. Pi-zewalski, i. p. 177, 

 pi. xxii. (1890). 



Except in its slightly larger size I can find, after careful com- 

 parison of a co-type of melauostoma with the types of curzonice, 

 no other distinguishing characteristics between these two species, 

 and possibly a larger series of the latter would prove them to be 

 identical. Blichner, in his original description, had apparently 

 overlooked 0. curzonice, as he only disbingnishes it from 0. daurica, 

 from which it differs in its yellowish under parts and black muzzle. 

 The general colour of the winter pelage above is sandy broA\Ta 

 grizzled with darker brown or blackish. Each hair at its base 

 is grey, shading to light bro^vn and ending in a dark tip. 

 Interspersed over the upper parts are long uniformly black hairs. 

 The under parts are dirty yellowish white. 



In summer the hairs wear down so that the light-brown 

 subterminal rings become more conspicuous, the black tips being 

 nearly or quite worn away ; the long and uniformly black hairs, 

 however, remain, so that the gTizzled appearance is not altogether 

 lost, but the animal becomes brighter and browner and the under 

 parts tend to become of a purer white. 



