192 On some new Forms of Ochotona. 



reason or anotlier it lias been confuseil witli 0. roylei, and 

 never distinguished till now. Blanford's specimens had 

 broken sUulls, so that he was not able to see the jjreat 

 differonce in size between it and royhi., while Bonhote 

 nnaccountably referred it to hodgsoni, a form nndoubtodly 

 synonymous with roi/lei, as may be seen by the figure of tho 

 skull given in the original descrijition. 



From royhi it is not only distinguished by its much 

 smaller size, but by its brown instead of grey colour, and the 

 absence of any seasonal fulvous mantle. 



But to 0. thihetana it is far more nearly allied, and can 

 only be separated by the smaller bullie. Possibly it n)ay 

 prove to be more properly a subspecies of thiheUinn, but I 

 should not be justified in assuming that intermediate speci- 

 mens occur without seeing material from the intermediate area 

 of Bhotan and South-western Tibet. 



The thihetana group is widely distributed over Tibet and 

 China, and the present forms its furthest western extension. 



Ochotona zappeyi, sp. n. 



Near 0. thihetana, but with narrower skull and less 

 uniformly brown back. 



Size about as in thihetana, though the skull is longer. 

 General colour lined blackisii grey, this colour covering the 

 greater part of the back. But the shoulders are w^ashed with 

 drabby, and there are large post-aural drabby whitish patches 

 on each side of the nape. Crown washed with dull drabby. 

 Ecirs with the proectote black at base, grey distally, while in 

 sikimaiia it is wholly black. Marginal part of inner surface 

 brown, inner part grey ; extreme edge white as usual. 

 Under surface greyish white, lighter and more sharply defined 

 than in thihetana, the chest, however, drabl)y brown as in 

 that animal. Hands and feet whitish instead of pale brown ; 

 sole-brushes blackish brown. 



Skull longer and narrower than that of thihetana, with 

 very narrow interorbital region and brain-case. Rudimentary 

 postorbital j)rocesses well marked in the single specimen. 

 Bullae narrower and a little longer than in thihetana, much 

 larger than in sikimaria. 



Dimensions of the type: — 



Head and body 170 mm.; hind foot 28. 



Skull : greatest length 39 mm.; condylo-incisive length 36; 

 zygomatic breadth 17*8 ; nasals 1'33 x 4'5 ; interorbital 

 bn.adih 3"7 ; post-squaniosal breadth 11"8; breadth of brain- 



