Mammals from East Africa. 125 



Type. Old female. Origiual number 1894. Collected on 

 February 12th, 1911. 



The very much larger skull and lighter-coloured pelage 

 are the chief points that distinguish this new form from the 

 allied race, C. gambianus kenyensis. 



Acomys kempi, sp. n. 



c?.1735; $.1736. Chauler Falls, Eusso Nyiro. 



Kelated to A. ifpiitus, Dollm., but very much paler in 

 colour and with a longer tail. 



Size of body rather less than in A. ignitus, skull con- 

 siderably smaller. Tail comparatively long. General colour 

 of upper surface pale orange-buff, washed Avith pale slate- 

 grey down the middle of the back. Flanks pale orange-buff 

 (between yellowish t^almon no. 1 and cinnamon no. 1, 

 ' Repertoire de Coulcurs '), very faintly speckled with 

 brownish, the general effect very like that occurring in 

 A. witherbyi, de Wint. As in A. ignitus and the other allied 

 species, the buffy tint on the flanks is sharply marked oft' 

 from the white nnderparts. Nasal region and forehead 

 washed with slaty grey. Backs of hands and feet dirty 

 white. Ventral surface white. Tail long and with well- 

 marked dorsal and ventral surfaces ; caudal hairs as in 

 A. ignitus. 



Skull smaller than that of ignitus, with a narrow brain- 

 case; zygomatic arches almost parallel; auditory bullje 

 small and uninflated, markedly different to the bulhe of 

 ignitus. 



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



Head and body 103 mm. ; tail lOG ; hind foot IG ; 

 ear 17. 



Skull: greatest length 28"4 ; basilar length STS ; con- 

 dylo-basilar length 23*7 ; coudylo-incisive length 25'5 ; 

 zygomatic breadth 12"5 ; interorbital breadth 4'5 ; breadth 

 of brain-case (across squamosal region) 12 ; length of 

 nasals 11 ; width of palate (inside m^) 3 ; length of palatal 

 foramina G'5 ; length of upper molar series 4. 



Hab. Chanler Falls, Eusso Nyiro. Altitude 3000 feet. 



Type. Adult female. Original number 1738. Collected 

 GO January 18th, 1911. 



This species is distinguished from A. ignitus by its far 

 paler colour, longer tail, and very much smaller skull with 

 less inflated bullae. In general colour it most nearly re- 

 sembles A. ivitherbyi, a species described by de Winton from 

 El Kowa, Soudan, but the dimensions of the two animals 



