the Genus Orice-tomys. 283 



Senegal to the S.E. Soudan and the country between the 

 Nile and the Congo. Southwards this species extends into 

 Southern Nigeria and the Welle Basin, its range partly over- 

 lapping that of the sleek-furred species of Western and 

 Central Africa. 



G. gambianas, as I understand it, is a comparatively small 

 species, in which the hind foot rarely measures more than 

 65 mm., while the condylo-basal length of the adult skull 

 rarely exceeds 67 mm. It has loose harsh fur, which varies 

 in density according to the subspecies. The general dorsal 

 colour is a rather cold grey, which may or may not be more 

 or less darkened along the spine and over - the rump by long- 

 black hairs. The ears are dusky and in conspicuous contrast 

 with the rest of the dorsal surface. The underpants are 

 white separated from the flanks by regular, though often not 

 very sharp, lateral lines of demarcation. The feet are whitish 

 above, with more or less extensive dusky markings, the 

 proximal half or third of the tail is dusky, the remainder 

 being white. 



The skull and teeth are normal ; the palate without a post- 

 terior median spine, but often with a minute median notch. 

 The bullae show a certain amount of subspecific variation in 

 size ; and more important variations, dependent upon the 

 development of the jaw-muscles, are discoverable between 

 the subspecies in the region of the infraorbital canal when 

 the skulls are studied with sufficient care. 



Four subspecies, inclusive of a new one described below, 

 are now known ; but others will probably deserve recognition 

 when further material comes to hand. These subspecies are : — 



1. G. g. gamldanus, Waterhouse. 



Gambia and Senegal ; type B.M. 55. 12. 24. 136 from 

 the Gambia. 



2. C. g. dichrurus, Osgood. 



Anambara River, S. Nigeria; type B.M. 5. 12. 1. 21, 

 ? adolescent. 



3. G. g. olivice, Dollman. 



Bornu, N. Nigeria ; type B.M. 11. 5. 12. 9, male. 



4. G. g. grahamiy subsp. n. 



C. gainbianns grahami, subsp. n. 



Type.— An adult male (B.M. 19. 3. 2. 1), collected on 

 November 1, 1918, on the Nuba Mountains, S.E. Soudan 

 (altitude 1500'), by Major C. Graham and presented by him 

 to the National Collection. No other specimen known. 



