92 



EINAR LÖNNBERG, MAMMALS COLLECTED IN CENTRAL AFRICA. 



and it is perhaps not certain that they are of quite the same race as the type from Gabun. 

 The above quoted cranial measurements have made it probable that the leucogaster- 

 Duiker living at Beni is larger than the one of the Stanley Falls district. 



The adult specimen of the present collection does not differ much from the young 

 one, but has a little brighter colours on the sides of the anterior part of the body. The 

 scapular region may be described as »otterbrown » finely grizzled with rufous, behind 

 this the sides are »fawn» (Dauthenay, 306, 1 &2) which gradually becomes brighter, al- 

 most »rustred» (Dauthenay, 318, 2) on the hind quarters at the sides of the black dorsal 

 band. Down on the hams the colour gradually becomes lighter (318, 1), and finally it 

 appears most similar to Rldgway's »pinkish cinnamon». A black band on the heel ex- 

 tends as a narrow dark streak to the outer of the lateral hoofs, and a similar dark streak 

 is seen on the front side of the metatarsus. 



Thomas has kindly communicated in a letter that all specimens of C. leucogaster 

 in the British Museum have a dark mark down the heel, and also that their fore-legs 

 are a kind of påle ashy grey brown. Thus the colour pattern of these specimens ap- 

 pears to agree with the typical oncs, and it depends then upon cranial dimensions, if C. 

 leucogaster from Beni possibly constitutes a different race, which cannot be decided 

 before adult skulls from the type locality have been described. 



Cephalophus castaneus arrhenii n. subsp. 



1 ? from Beni, Jan. 1914. 



This specimen is no doubt related to C. castaneus Thomas typically from Cameroon, 

 but also described by the same author from Congo. 1 There are, however, differences as 

 well with regard to cranial dimensions as in colour which are too great, and too important 

 to permit an identification, the specimen of the present collection being much darker and 

 much smaller, as may be seen from the following table af measurements. 



C. c. arrhenii 



S from Ben 



C. castaneus 



c? from 

 Mukirii- 



hungu 



Greatest length of skull 175 mm. 



Basal length 154,5 » 



Zygomatie width 76 » 



From orbit to tip of premaxillary 88 » 



Upper molar series | 54 » 



205 mm. 

 176,5* ; 



90 • 

 105 



59,6 » 



measurements récorded : 



hy S.iöstedt by Thomas 



170 mm. 

 85 

 99 

 56 



179 mm. 

 90 

 103 



59 



The considerably greater dimensions of C. castaneus IxMome perhaps still more 

 conspicuous if some other measurements of skull dimensions are compaml. Kor doing 

 so I have unfortunately only an adult male skull of G. castaneus from Miikimbnngu, 

 Lower Congo, for comparison, while the present female skull from Beni is still compara- 

 fcively young as it has not yet changed its milk-jiremolars, but the tliird molar is already 



1 Ann. d. Mus. du Congo, T. II, Fasc. 1. 



