346 Mr. G. Dollman on Aivicanthis abyssinicus 



regards the ventral colouring. Tail a little longer and more 

 hairy than that of rubescens. 



Skull very like that of ahyssinicus, rather heavier in build, 

 with a slightly larger brain-case. Nasals in type specimen 

 shorter than in rest of series. 



Dimensions in millimetres (measured in the flesh) : — 



Averajye of 



10 adults. Max. Min. 



Head and body 155 170 140 



Tail 117 123 1]5 



Iliudfoot 29 30 27 



Adult skull (type) : greatest length o5*5 mm. ; basilar 

 length 29'5 ; condylo-incisive length 33'5 ; zygomatic 

 breadth 18'3 ; interorbital constriction 5 ; squamosal breadth 

 of cranium 14; length of nasals 12*5; palatilar length 16; 

 length of palatal foramina 7 ; alveolar length of upper molar 

 series 7. 



Type locality, Kisumu, British East Africa. 



Type in British Museum, no. 10. 4. 2. 29. 



Specimens belonging to this race have been received from 

 the following localities : — Kisumu, Mumias, and Kirui 

 (Elgon), British East Africa. 



(10) Arvicanthis abyssinicus nairobcB^ Allen. 



1909. A7-vicanthis nairobce, Allen, Bull. Am. Mus. N. II. p. 1G8. 

 1909. Arvicanthis ahyssinicus nairobcp, Wrought. Auu. & Mag. Nat. 

 Hist. (8) iv. p. 637. 



Smaller in size than any of the preceding forms, with 

 grey-coloured hands and feet and greyisli-white under 

 surface. 



Size of body small (136 mm.) ; hind foot and tail short. 

 General colour much as in typical abyssinicus^ but speckling 

 rather finer. Flanks rather paler than back, washed with 

 buff. No dorsal stripe. Backs of hands and feet greyish. 

 Under surface greyish white, markedly less buff-coloured 

 than in prceceps or neumanni ; hairs of belly with long 

 white tips. I'ail shorter and less hairy than in the larger 

 forms; upper surface dark blackish brown, underside dirty 

 white. 



Skull very similar to that of nubilans in general shape, 

 dimensions rather less. Molar teeth narrower than in the 

 preceding species. 



