146 ANTELOPES 



it becomes worn off in old individuals so as to show the whitish under- 

 fur, or even the naked skin, at the base of the tail. The general 

 colour of head, body, and limbs is dark blackish brown ; but the 

 muzzle, cheek, chin, and the tips of the ears are whitish ; while on the 

 middle line of the loins is a long yellowish triangular stripe, extending 

 as far forwards as the middle of the back, and in old animals forming 

 a light rump-patch posteriorly. 



In quite young specimens all the hairs of the hind part of the 

 body, except in the region where the light triangle is subsequently to 

 appear (in which they are black-tipped), terminate in white tips ; and 

 the rump-patch, which eventually becomes whitish and partly bare, 

 is clothed with long black hairs. 



This species ranges on the west coast from Sierra Leone to the 

 Gaboon and Angola ; but how far into the interior (at all events in 

 its typical form) is still unknown. The colour-changes mentioned 

 above render it often difficult to determine what variations are due to 

 immaturity and what to distinctness of type. Consequently the 

 determination of allied species and races is beset with difficulties. 

 The important part to bear in mind is, however, that the under- 

 mentioned forms, whether they be distinct species or not, prove that 

 members of the yellow-backed group extend right across the forest- 

 region into the Ituri district and Rhodesia. 



The maximum recorded horn-length is 7 inches. 



In Notes from the Leyden Museum, vol. xxii. p. 187, 1900, Dr. 

 F. A. Jentink has suggested the name of CephalopJius thomasi for the 

 Congo representative of the yellow-backed duiker, and C. sdateri for 

 another phase in which the horns are curved. 



Very little is known with regard to the habits of this species and 

 its immediate relatives. 



RHODESIAN YELLOW-BACKED DUIKER 



{Cep/ialop/ius coxi) 

 C/nlnisimazve, RHODESIA 



In the Proceedings of the Zoological Society for 1902, vol. i. p. i, 

 Mr. O. Thomas referred the skin of a large duiker from north-east 

 Rhodesia to the yellow-backed species ; remarking that " no differences 

 of importance were perceptible between the Rhodesian specimen and 

 examples from West Africa." Four years later Dr. F. A. Jentink 



