SCIENTIFIC RESULTS FROM THE MAMMAL SURVEY 



i-> 



Bescni'ption: — This is a relatively long-tailed race, with usually a 

 short, thin, rather harsh, though not spiny coat. The general 

 colour of the back is near " cinnamon brown " or tawny, greyer 

 in young or quite unbleached specimens, yellower when older, much 

 worn or bleached. The tmderparts are pure white or cream-colour- 

 ed, the ventral hairs being light to their bases. The hairs around 

 the genitalia are, however, often ochraceous. The feet are light, 

 sometimes quite white, sometimes tawny above. The tail is a 

 uniform light brown. 



The mammas were counted in 37 females; in 36 the formula was 

 2-3=10, 1 had 11 mammte. 



In the 72 specimens in adult pelage from Bihar and Orissa, 

 enumerated above the head and body length varies between 134 

 and 174 mm. The Collector's measurements give the following 

 averages and percentages : — 



Average of 72 adults from Bihar 



and Orissa:— 159— 215— 31-6— 23-2 



Average of Head & Body length : 100— 135— 19-9- 14-6 



The specimens from all localities mentioned conform closely to 

 these averages. The following table shows the variation of propor- 

 tions with growth and may be compared with those given above : — 



Head & Body. 

 mm. 



No, of specimens. 



Average 7o of Hfsad & Body formed by 

 H. & B., Tail, Hind-foot, Ear. 



112 



134 to 138 

 142 to 149 

 150 to 159 

 160 to 169 

 170 to 174 



100— 154— 25-9- 17-9 

 100—135—22 —15-4 

 100— 141— 21-2- 15-6 

 100— 137-5-20'3— 14-9 

 100— 136— 19-6— 14-5 

 100— 127— 19-2- 14-5 



The skull is slightly smaller than in European races of rattus; 

 (average condylo-basal length 39-5, instead of 40*5) ; the cranial 

 and zygomatic widths are, therefore, relatively a little greater. Its 

 chief peculiarities appear to be the outcome of more powerful 

 temporal muscles and slightly larger cheek-teeth. Ti^.us the least 

 posterior inter- temporal distance (dimension 7) is less, both in 

 relation to the condylo-basal length and to the cranial width ; the 

 temporal lines are in contact with the ends of the interparietal in 

 adults, so that the parietals have no inter-temporal connection 

 with the supraoccipital ; the temporal wing of each parietal is 

 large, its length being fully equal to half the length of the squa- 

 mosal. The palatal length, diastema, palatal foramina, masseteric 



