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monkeys, which he identifies witli aterrimus of Oiiilemans, are almndant in Uganda. 

 The fully adnlt individuals are distinguished from the typical alhigcna by the very 

 dark brown (instead of light grey) shoulders ; but the young are uniformly black. 



If, then, it be thought advisable to separate, either subgenerically or generically, 

 these black and crested mangabeys with dark eyelids from the smooth-headed 

 Cercocebi with white upper eyelids, we shall have the following forms : viz., — 



1. Semnoccbiis albigeiia alhiyena. Head-crest short and occipital in position ; 

 a superciliary fringe ; whiskers greyish. West Africa. 



2. Semnocebus albigena aterrimus. Head-crest long, and occupying whole 

 middle portion of head ; a long superciliary fringe ; whiskers small, greyish, and 

 not concealing ears, and the hair on nape and shoulders blackish-brown. Typically 

 from the Congo district. 



3. Semnocebus albigena rothschildi. Head-crest j)eaked and occupying middle 

 of head ; no superciliary fringe ; large whiskers in front of and partly concealing 

 ears ; colour wholly black, or nearly so. Probably from the Congo. 



4. Semnocebus alhiqena johnstoni. Head-crest as in alb. albigena, but super- 

 ciliary fringe shorter, and whole of npper-jjarts uniformly black. Lake Tanganyika 

 district. 



It may be added that if C. claysogaster and C. hagenbecki are retained in 

 Cercocebus, the ordinary definition of that genus must be modified iu regard to 

 the statement that the hairs are never annulated ; and in the case of the male, 

 at least of the latter, in respect to the universal presence of flesh-coloured upper 

 eyelids. 



In conclusion, 1 may mention that a large adult male of this species (locality 

 unknown), recently presented to the Zoological Society, agrees with the typical 

 albigena in the length of the hair and its grey colour on the sides of the head, chest, 

 and shoulders, as well as in the almost completely bare face, and the absence of 

 whiskers iu front of the ears. There is, however, no forwardly projecting fringe of 

 long hairs above the eyes, which is so conspicuous in the type skin of albigena, 

 as well as in Dr. Gray's figure of the same : and the crest of hair extends all 

 over the head, and is considerably more voluminous than in the latter, although 

 entirely lacking the peaked form which is disjilayed iu the s])ecimen here figured. 

 It is difiicult to believe that these ditt'erences are individual or due to age ; and if 

 they are not, this monkey indicates a distinct race. 



