1904.] MOUSE-HARES OF THE GENUS OCHOTOXA. 2l3 



the general colovir. Intermixed with the fur projjer are some 

 long black bristles. I fancy that in its changes of pelage this 

 species closely follows 0. ladacensis, for at the end of summer it 

 is of a bright golden buff" due to the wearing off of the terminal 

 portions of the winter pelage described above. The long black 

 bristles, however, do not wear down and thus become more 

 conspicuous. 



The shidl, which is well figui-ed by Blichner, is rather short in 

 the muzzle, giving it a broad and thick-set appearance. The 

 muzzle is both short and narrow, and possibly in correlation with 

 this we find the anterior terminal portion of the nasals tending 

 to turn upwards to a marked extent and having a bi'oad vertical 

 portion. The foramina are as in 0. riifescens. 



Dimensions of skin (after Biichner). Head and body 240 mm. ; 

 hind foot 42 ; ear 19"5. 



Skull. Greatest length 44 mm. ; basal length 33 ; zygomatic 

 breadth 27*2 ; length of nasals 14"3 ; length of molar series 10. 



Habitat. Northern Thibet. 



This sjDecies may easily, apart from skull-characters, be dis- 

 tinguished from 0. Iculacensis, with wliich alone it could be 

 confused, by the ears being yellow and not rufous, the tips white 

 not black, and the under parts snowy white and not yellowish. 



OCHOTOXA PUSILLA (Pall.). 



Lejnts ■piisillus Pallas. Glires, p. 37, pi. i. (1778); Schreli. 

 Saugth. iv. p. 906, pi. 237 (1792). 



Lagomys pusillus (Pall.), Desm. Mamm. p. 353 (1820); Guv . 

 Regne Anim. p. 219 (1829) ; Waterh. Mamm. ii. p. 19, pi. i. 

 fig. 2 (1848). 



This is the smallest species of the genus as yet known. The 

 general colour above, which is uniform, is dark brown, grizzled 

 with white where the whitish median portion of each hair shows 

 through. Under parts white ; ears and feet gi'izzled, the former 

 having a conspicuous ring of white hairs growing from their 

 inner margin. 



The skull. — From the material at hand I am unable to say much 

 about the skull, which is small but well proportioned, the muzzle 

 being rather stout and shoit. The foramen is very typical of the 

 group in which I have placed it. 



Dimensions (approx. from stuffed specimen). Head and body 

 145 mm. ; hind foot 27 ; ear 14. 



Skull. Zygomatic breadth 20 mm. ; length of nasals 12 ; length 

 of molar series 7 ; length of palate from henselion 8"5. 



Habitat. S.E. Russia and thence eastward to Siberia. 



Material is so scarce that it is impossible to say much concern- 

 ing this species, which may be recognised by its small size and 

 the white rims to the ears, in which characters it approaches 

 0. hodgsoni from Kashmir. 



