8 



on each temple white. Throat, uuder-part of the body and mside of 

 the legs whitish ; the front of the shoulders, outside of the limbs, end 

 of the tail blackish. Ears, the middle of the back, and upper part of 

 the tail, rufous. 



In the British Museum collection there is a half-grown specimen 

 of this species which died in a menagerie near London, and was said 

 to have come from Western Africa. 



The Black-cheeked Monkey is easily known from Cercopithecus 

 nictitans by its yellow punctulated fur and cordate form of the spot 

 on the nose ; the latter character equally distinguishes it from Cerco- 

 pithecus petaurista, from which it is also separated by the black- 

 ness of its cheeks and the greyness of the outside of the limbs, and the 

 redness of the middle of the back and the tail. 



This species was indicated in the 'Annals of Natural History' for 

 184.5, but is redescribed and figured here for the purpose of com- 

 parison with the next. 



Cercopithecus ludio. The Ludio. 



(Mammalia, PI. IX. fig. 2.) 



Blackish, minutely yellow grisled ; face, temple, crown of the head, 

 shoulders and fore-legs, black ; outer side of the hinder legs and end 

 of tail blackish ; large oblong spot on the nose white ; throat, upper 

 part of the inside of arms, and lower side of the body, whitish ; rump 

 and under side of base of tail dark reddish brown. 



Hab. West Africa. 



In the British Museum there is a nearly full-grown specimen of this 

 species, which was procured from a menagerie in Liverpool, and was 

 said to have been brought from the west coast of Africa. 



This is at once known from two other species which have the fur 

 punctated with yellow, viz. C. petaurista and C. melanogenys, by the 

 large size and erect oblong form of the white spot on the nose, and 

 especially by the absence of any white on the cheek or temples ; it i% 

 easily distinguished also by the general black tint of the fur, and 

 especially by the red hairs of the rump. 



In the course of last year there was exhibited in the Gardens of the 

 Society a short-tailed American monkey, which was regarded by several 

 eminent zoologists as a species of Cebus which had lost part of its tail ; 

 but there was a peculiarity in the position of the thumb as regarded 

 the fingers, which at once showed that whatever might be the natural 

 length of its tail, it evidently did not belong to the genus Cebus as at 

 present restricted. The examination of the animal after death showed 

 that it was a most distinct genus, and nearly related to, if not a variety 

 of, Brachyurus Oiiakari of Spix. 



I may observe that the genus Brachyurus was established by Spix 

 in his work on American Monkeys for two species, viz. 1 . the Simia 

 Chiropotes of Humboldt (the S. Saguluta of Trail), which has been 

 generally referred to the genus Pithecia ; and 2. Brachyurus Ouakari. 

 Spix in the same work restricted the genus Pithecia to the Saki or 

 Long-haired American Monkeys. 



The examination and comparison of the skull of the short-tailed 



