new African Rodents and Insectivores. 151 



nape and sides of the back near " cinnamon-drab " instead of 

 tawny, the blackish median saddle-mark not so drab or so 

 strongly contrasted. Under surface similarly pure sharply 

 defined white. Limbs rather more completely whitish. 

 Tail equally long and pencilled terminally, but, instead of 

 being dark above quite to the tip as in D. ferrugineus, the 

 end for from 1 to 3 inches is white above as well as below, 

 forming a white terminal pencil. 



Skull generally similar to that of D. ferrugineus, but the 

 supraorbital ridges form more distinct postorbital projections, 

 overhanging the temporal fossae. In ferrugineus the ridges 

 are, as a rule, straight, without projections. Palatal foramina 

 averaging shorter. Opening of posterior nares narrower, the 

 median notch of the palate more sharply pointed. 



Teeth as in D. ferrugineus. 



Dimensions of an adult female from Poko, no. 1134 (type), 

 taken on skin : — 



Head and body 148 mm, ; tail 205 ; hind foot 35'3. 



Skull : greatest length 36'7 ; condylo-incisive length 32'5 ; 

 zygomatic breadth 15 ; nasals 14 ; interorbital breadth 6 ; 

 breadth across brain-case 14 ; palatilar length 16'7 ; palatal 

 foramina 5*5 ; upper molar series 5*8. 



Hob. Upper Ituri and Upper Welle. 



This Eastern representative of the Deomys ferrugineus of 

 the Cameroons and Gaboon is readily distinguishable by its 

 duller and paler colour, its white-tipped tail, and the cranial 

 characters above described. 



Named in honour of its collector Dr. Christy, who informs 

 me that it is a water-rat living along the edges of the rivers. 



Sylvisorex gemmeus Irene, subsp. n. 



Size, proportions, and cranial characters as in true gemmeus 

 of the Lado Enclave, but general colour pale olive-brown. 



Dimensions of type (measured in flesh) : — 



Head and body 60 mm. ; tail 68; hind foot 13'5 ; 

 ear 9. 



Skull : condylo-incisive length 17'2 ; breadth of brain- 

 case 7'8 ; upper tooth-row 7'4 ; p^-m 2 3"8. 



Bab. Southern Uganda and Upper Ituri. Type from 

 Kaganbah, Uganda. Alt. 1600 m. Two other specimens 

 obtained by Dr. Christy at Poko, on the Welle, and Medje, 

 on the Upper Ituri. 



Type. Adult male. B.M. no. 11. 12, 3. 56. Original 

 number 2344. Collected 10th July, 1911, by Robin Kemp. 



The general colour of true gemmeus is said to be " seal- 

 brown," a very different colour from the pale olive-brown of 

 this form. 



