376 Mr. R. C. Wrouj^liton on 



pelure, coloration, &c. mucli resembling vaUda, Boo. General 

 colour above a pale brown, mncli shaded with black, as in 

 raliJa, but this black tinge disappearins; laterally much more 

 suddenly than in that species. Individual hairs of back 

 13-15 mm. long, dark slate for fully j of their length, then 

 buff, with black tips. Under surface white (the hairs white 

 to their bases), sharply defined. The black tinge of the back 

 produced forward over the top of the head and over the whole 

 face between the eyes, as in vnlida, but the black streak 

 from the eye to the ear of that species not present. Tail 

 much longer than head and body, almost black above, almost 

 ■white beneath, throughout its whole length ; little or no tuft 

 at apex. 



Skull large for the size of the animal, long and narrow. 

 Upper incisors with a well-marked groove outside the median 

 line. 



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



Head and body 145 mm. ; tail 174; hind foot 35 ; ear 20. 



Skull : greatest length 42 ; basilar length 33 ; brain-case, 

 breadth 16 ; interorbital breadth 7 ; diastema 12*5 ; molar 

 tooth-row 6 ; bullae 11. 



Hah. S. Nigeria. 



Type. B.M. no. 5. 12. 1. 8 (a very old ? ). Collected by 

 Mr. Robin Kemp, August 21st, 1905. 



This species is intermediate in size between vaUda, Boc, 

 from Angola, and grociJis, Tiios., from Gambia, the only two 

 species hitherto recorded from the western side of the continent. 

 ]t is interesting to note that by the absence of a tail-tuft and 

 its comparatively long tail it is allied to the South-African 

 rather than to the N. -African, or even Mid-African, forms. 

 In ihe Angolan forms of Tatera the head and body and the 

 tail are practically of equal length. 



7. ArvicaniMs rufinus. 

 Mus riifmus, Temm. Esquisses, p. 163 (18o8). 



S . 5. 12. 1. 9, 14, 15 ; ? . 5. 12. 1. 10-12, 10. Agoulerie, 

 Anambra Creek. 



Temminck''s description of his Mus rujinus from Guinea 

 was admittedly based on semi-adult specimens and is not 

 very full ; but Mr. Thomas, who has seen the type specimen, 

 assures me that it is undoubtedly an Arvicanthis. The type 

 locality was Elmina, on the Gold Coast. Amongst the 

 specimens of this series are some which have the usual pale 

 ground-colour of the back a pale buff, while the rest have it 



