On a new Rat from Simla. 473 



Under surface sparingly setose, the hairs longer than on the 

 upper surface. The chief distinction between the sexes is 

 that in the female the pygidium is extremely short ; in the 

 male it is twice as long. 



Ootacamund {G. A. Barher, no. 205). In the collections 

 of the British Museum, Cambridge Museum, and D. Sharp. 



Cambridg'e, 

 March, 1903, 



LXIV. — On a neiu Rat of the Mus rufescens Group 

 from Simla. By J. LEWIS BONHOTE, M.A. 



When revising the Oriental rats of the Mus rattus group a 

 short time ago I came across a series of eleven from Simla, 

 differing, so far as I know, from the numerous rats of this 

 group which have already been described. I therefore 

 propose to describe it under the name 



Mus vicerexj sp. n. 



Similar in size to typical Mus rufescens, but with shorter 

 tail. 



General colour yellowish grey, lighter on tlie flanks and 

 darker on back, interspersed with long black hairs which, 

 when seen in certain lights, have a greenish gloss. Under- 

 parts and feet white, the facial portion and top of the nose 

 very grey. Tail of medium length, not exceeding that of 

 the head and body, markedly bicolor and well clothed with 

 numerous very fine hairs. Ears large and uniform dark 

 brown in colour, having a very narrow line of white hairs 

 round the extreme margin. Fur thickly beset with long and 

 slender spines. 



The skull resembles that of M. rifescens very closely ; 

 it differs, however, in the greater breadth of the nasals, 

 Avith which is correlated a stouter muzzle. The audital 

 bullse are rather less inflated on their outer surface, giving 

 them the appearance of lying more obliquely on the skull. 



Dimensions (of type) from dried skin : — Head and body 

 173 millim. ; tail (tip broken) 130 ; hind foot 33 ; ear 23. 



Skull : greatest length 42 millim. ; basal length 34 ; 

 palatal length 20 ; length of nasals 15 ; breadth of nasals 

 anteriorly 4-5 ; greatest breadth of muzzle 7 ; zygomatic 

 breadth, approx., 21 ; greatest breadth of brain-case 16. 



JIab. Simla. 



