228 J. Anderson — On the Suh- Genus Nesokia. [No. 4j 



Measurements in the flesh, of male and female. 



Length of body and head, 8"'20 6''-05 



tail, 6''-45 5"-55 



Total length, 14"-65 11" 60 



Length of hind foot, 1".30 1 "-30 



Height of ear, 0''-83 0"-75 



Breadth of ear, 0''-75 0''-65 



The females are distinguished by the presence of 8 pairs of mam- 

 mary teats. Two in the inguinal region, four on the sides, one pair in the 

 axilla and one pectoral pair. 



The skull is distinguished from the skull of the nearly allied form 

 M. (N.) providens by the characters already stated, and from the skull of 

 M. hardwichii it differs in its considerably narrower incisors and smaller 

 and more irregularly laminated molars, and by its long and open anterior 

 palatine foramina. It is also a more arched skull. The incisor teeth are 

 orange, occasionally brilliantly so, but generally white towards their tips, 

 whilst in some these teeth are nearly white in both sexes, but the teeth of 

 the males are usually the most coloured. 



The nasals vary considerably in length and breadth. Compared with the 

 skulls of ordinary mice, shortness of muzzle is one of its most distinguishing 

 features, associated with expansion of the zygomata and general rotundity. 

 The skull of the male is always considerably larger than that of the female. 

 Among males found among the native huts, I have observed two types of 

 skull, one larger than the typical form, but the animals in other respects 

 were identical with other males conforming to the ordinary type of skull. 

 I have never observed these more elongated skulls in females, but if they 

 do occur I would be disposed to attribute the variation to inter-breeding 

 with Mus decumanus. 



The adult rat, in its external appearance, has a strong resemblance to 

 M. decumanus^ when the depth of its muzzle and longer tail are overlooked, 

 and a superficial observer at first sight would be disposed to regard them as 

 one and the same species. 



It is distinguished from M. (N.) Jiardwiclcii, by its much longer tail, 

 by its coarser and much darker pelage, narrower incisors and larger ears, and 

 these features and its much smaller feet distinguish it from M. (JV.) scullyi. 



It is a larger animal than M. {N.) providens^ than which it has some- 

 what larger ears, a larger head, and broader incisors. 



The Indian Museum possesses examples of this species from Ghazipur 

 in the North-West of India, from Dacca, Cachar and Midnapore, and 

 numerous specimens from Calcutta and its neighbourhood. 



