neio African Mammals. 85 



Hab. Yambuya, Aruwimi R., Congo. 



Type. Adult skin. B.M. no. 0. 3. 2. 1. Collected during 

 the Erain Relief Expedition and presented by J. S. Jameson, 

 Esq. 



This very peculiarly coloured species cannot be confused 

 with any hitherto described. 



Protoxerus stangeri signatus, subsp. n. 



Agreeing with P. s. eborivorus, Du Chaillu, in all essential 

 respects, but the grizzled blackish line at the lower edge of 

 the upper colour on the flanks quite without the fine 

 white tickings, and consequently deep uniform black, well 

 contrasted with the grizzled brownish above it, and the 

 fine whitish line which separates it from the belly. Posterior 

 back of the somewhat warmer tone found in P. s. centricola. 

 Feet rich rufous. Hands also tending towards rufous, which 

 is unusual in this group. 



Hab. Central and Southern Congo. Type from Lodja, 

 Upper Lukenye R., Southern Congo. A second specimen 

 from Ikau, Central Congo. 



Type. Adult male. B.M. no. 9. 12. 12. 7. Collected and 

 presented by Mr. E. Torday. 



A special Genus for Mus univittatus, Peters. 



The position of the peculiar W. African rat described by 

 Peters under the above name has long been doubtful, and it has 

 sometimes been placed in Mus and sometimes in Arvicanthis. 

 It differs, however, from both so much that 1 think it should 

 form a special genus, which may be called HYBOMYS. 



Externally it resembles Arvicanthis in its black dorsal line 

 and shortened fifth hind toe (not so much shortened, however), 

 but differs by its much more slender build and its almost 

 naked tail. Mammae — 2 = 4. 



Its skull is peculiarly bowed, of quite different shape to 

 that of either Arvicanthis or Mus. Its molars are, on the 

 whole, like those of the former. 



Good accounts of it have b en given by Peters (MB. Ak. 

 Berl. 1876, p. 479) and Tullberg (MT. Ges. Upsala, 1893, 

 p. 20, with figures of the skull and teeth), so that further 

 description is not now necessary. 



Arvicanthis wroughtoni, sp. n. 



Allied to the common E. African A. massaicus, but the 

 dark ground-colour of the hack black instead of brown, so 



