SCIENTIFIC RESULTS FROM THE MAMMAL SURVEY. 403 



Irrawadi Valley (B. M. serial No. 14.7.9.) — 

 Kyoiik Nyoung. 



•164 3400 2 , 29 July 184-232-38.5-25 = 100-126-18.2-13.6. 

 Ngap5dnin. 



•165 3416 2 , 2nd Aug. 184-206-34-22.= 100-112-18.5-12. 

 North Shan States (B. M. serial No. 14.7.8.)— 

 Hsipaw, 



•37 3138 d, 10 June 176-194-32-22 = 100-110-18.2-12.5 5:^ oz. 

 Mingun (B. M. serial No. 14.7.9-)— 

 .166 3240 c?, 9 July 1913 187—220—34 —22 



„ 180—182—34.5—22. 

 „ 187—182—33 —22. 

 ,, 173_194_32 —24. 

 172—188—32 —23. 

 170—201—32.9—21.7. 

 % of head and body :^.100— 118— 19.4— 12.8. 

 The skull is chiefly remarkable for the large size of the auclital 

 bullae ; comparison in this respect with other Burmese forms is 

 made in the subjoined table ; the other cranial dimensions are 

 given in part III in the tables II (e) and II (h). 



Average of 11 adults 



Dark bellied House Rats of India and Ceylo>\ 



For reasons mentioned in the introduction to this paper, and in 

 the descriptions of R. r. narhaclce and r. girensis, I share Mr. 

 Wroughton's view that, unlike the wild white bellied races of li. 

 rcdtus, the dark bellied House Bats of India and Ceylon are essen- 

 tially parasites. In part, they seem to have arisen, by domestica- 

 tion, directly from the wild white bellied races of the country ; in 

 part, they are apparently the descendants of rats imported from 

 abroad ; and in part, they must be regarded as products derived 

 from the interbreeding of the two classes just named. I devoted 

 much time and trouble to an attempt to work out the exact relation- 

 ship of the dark bellied rats of each district ; but I arrived at no 

 definite conclusion other than that just expressed. 



14. Ratius rattus rufescens. Gray. 



1837. Mus rufescens, J. E. Gray, Ann. Mag. N. H., I, p. 577. 

 1912. Upimys nifescens, Wroughton, Rep. No. 1, J. Bomihay N. 



H. Soc, xxi, p. 405, and subsequent reports. 

 il 



