486 Mr. G. Dollman on the 



Britisli -East Africa ; these specimens represent an entirely 

 now species, which is liere described as 



Acomys nubiliis, sp. n. 



About equal to Acomys wilsonl in size, but with longer tail 

 and very much darker in general colour. 



Size of body less than in t\\Qi(j)iitus i\x\A pidchellns groups, 

 more as in the short-tailed wilsoni ; tail fairly long, measuring 

 fiom 65 to 07 mm. in length, and thus much longer than in 

 the other small species where the tail very rarely exceeds 

 50 mm. in length. 



General colour of dorsal surface dark sepia-brown, slightly 

 speckled with buff, but not exhibiting the marked speckled 

 etlect found in wilsoni and ahlutus. Flanks pale buff 

 speckled with dark brown. Backs of hands and feet dirty 

 white. Entire underparts white. 



Skull very much like that of wilsoni, slightly larger 

 throughout, with a rather broader brain-case. 



Dimensions of the type (measured in the fiesh) : — 



Head and body 83 mm. ; tail 65 ; hind foot 14 ; ear 12. 



Skull of type badly broken; the following dimensions 

 are those of another specimen, No. 1477, from the type- 

 locality : greatest lengtli 25'4; condylo-incisive length 22'4; 

 zygomatic breadth 12 ; interorbital constriction 4'5 ; breadth 

 of brain-case 12; lenglh of palatal foramina 5'8; length of 

 upper molar series 4. 



This specimen (No. 1477) is exactly similar to the type 

 in general colour, but I have not been able to use it as a 

 tvpe, since the tail is badly broken. 



Ty/>e. Adult, Original number 1481. Collected June 

 14th, 1913. 



This striking and distinct species is immediately dis- 

 tinguished from A. unlsoni by its very much longer tail and 

 darker colour ; in general colour nuhtlus is darker than any 

 of the other East African Acomys, with the exception of the 

 slate-coloured ^ercifaZi. It is a little difficult to decide to 

 which group this species belongs, and for the present it seems 

 most satisfactory to regard it as a link between the large 

 long-tailed igniius group and the small short-tailed wilsoni. 



The following are the various forms of Acomys now 

 recognized in British East Africa : — 



1. Acomys ignitus, DoUm., originally described from speci- 

 mens collected by Mr. Kemp at Voi, has since been 

 found by Mr. Percival at various localities between 

 Voi and the coast. There are now before me specimens 



