594 Mr. P. S. Kersliaw 



on 



31. Rattus {^thorny s) sp. 

 S ' K. 54. Mbotio, near Itigi, Singida. 



Allied to the chrysophilus group, but with smaller feet. 

 The skull is unfortunately missing. 



This opportunity may be taken to describe a new species 

 of rat recently received from Uganda. It may be called 



Rattus sojnereni, sp. n. 



A small mouse-like form with tail equal in length to 

 head and body. 



This rat bears a superficial resemblance — except, of course, 

 in tail and feet — to a young Taterona, the usual streaked 

 mouse-brown of the back passing into the lighter and richer 

 tawny of the sides till it meets the sharply separated pure 

 white of the underparts, the hairs of wliich are white to 

 their bases. Hands and feet white. Tail thickly clothed 

 throughout its length with extremely short hairs, brown 

 above, whitish below. 



The skull is very similar to that of R. blainei, from Bahr- 

 el-Gliazal, but the zygomatic plates are set more vertically, 

 causing the infraorbital foramina to be narrower. Also the 

 anterior internal cusp of m^ is somewhat reduced. 



Dimensions of the type : — 



Head and body 93 mm. ; tail 93 ; hind foot 20 ; ear 15. 



Skull : condylo-incisive length 25 ; basal length 25 ; 

 breadth of brain-case 11 ; nasals (median line) 9*5; inter- 

 orbital breadth 4"8 ; upper molar series 4'5. Palatal fora- 

 mina as in R. blainei extend back to about the centre of 



Hah. Kabaroni, North Bugishu, Bukedi District, Eastern 

 Province, Uganda, in the western foot-hills of Mount Elgon. 

 Caught in grass on the mountain side, 7000 feet. 



Type. Young male. Collector's number 108. B.M. 

 no. 22. 12. 13. 31. Collected by Mr. W. N. van Someren, 

 13th February, 1922, and presented to the British Museum 

 by the Chief Sanitation Officer, Entebbe. 



The specimen, judging from the teeth, is young, and has 

 clearly not grown to its full size. Unfortunately it is a 

 male, so that the mammary formula has yet to be ascer- 

 tained. Its affinities appear to be with the group of small 

 multimammate rats, such as R. blainei and gambianus. 



32. Leggada betla^ Thos. 



S. K. 41. Jumbe Abdullah Eunge's, Mkindo River, 

 Morogoro. 



K. 213. No data. 



