336 Mr. G. Dollman on Arvicanthis abyssinicus 



■with white. No ocliraceous 

 or buft'-coloured suffusion. 



(Nairobi.) (10) a. nairobee, Allen. 



b^. Backs of hands and feet 

 orange-buft". Ventral sur- 

 face grey, washed with 

 buffy white. General co- 

 lour of back yellowish olive, 

 mixed with black and oclira- 

 ceous. (Naivasha.) (11) a. praceps, Wi'ought. 



c*. Backs of hands and feet 

 brownish, mixed with buff. 

 Ventral surface greyish 

 white, tinted with pale butf. 

 General colour of back dark 

 ochraceous. (Irangi, Ger- 

 man E. Africa.) (12) a. nentnamn, Matsch. 



c. Size of bod}' small; length of head and 



body less than 135 mm. 



o^. Size larger; length of head and body 



more than 125 mm. 



a^. Geneial colour greyish olive, 



faintly tinged with pale bull. 



Backs of hands and feet grey. 



Ventral surface greyish white. 



(Rumruti, Laikipia Plateau.) . . (14) ruiiiridi, DoUm. 



b^. General colour sandy ochraceous, 



strongly tinged with bull". Backs 



of hands and feet white, tinted 



with bufi'. Belly buffy white. 



a^. Tail longer, 122 mm. in length. 



Skull larger, greatest length 



34 mm. (Chanler Falls, Eusso 



Nyiro.) (17) chanleri, Dollm. 



h^. Tail shorter, averaging 99 mm. 

 in length. Skull smaller, 

 greatest length 30 mm. (So- 



maliland.) (15) sovialiats, Thos. 



fe'. Size smaller; length of head and 

 body less than 125 mm. (Eusso 

 Nyiro, E. Africa.) (16) reptans, Dollm. 



(1) Arvicanthis iesticularis, Sund. 



Isomys testicularis, Sundevall, Vet.-Akad. Handl. p. 221 (1843), 



Size comparatively large, tail very long. General colour 

 of dorsal surface pale sandy ochraceous lined with black. 

 Dorsal stripe narrow and ill-defined, in some cases entirely 

 absent. In bleached individuals the ochraceous colouring is 

 much more evident, especially on the hind-quarters and 

 posterior part of back. Flanks rather lighter than back and 

 more buffy. Nasal region orange-buff, the buff colour in 

 some cases extending back on to the face. Ears clothed with 



