XVII MANGABEYS AND GUENONS 565 



Macaques and Cercopithecus, giving to them the greenish hue 

 which characterises so many of the last two genera. There are 

 no laryngeal air sacs as in the Macaques. There are not more 

 than seven species. 



The genus Cercopithecus (the Guenons) represents in Africa 

 the Oriental and Palaearctic Macaques ; the genus has a long 

 tail. The cheek pouches are larger than in the genus Macacus. 

 The ischial callosities are less extensive than in that genus. A 

 tooth character also distinguishes this genus from MacacAis ; the 

 last molar of the lower jaw has, as a very general rule, only 

 four cusps instead of the five which are found in Macacus. The 

 supraciliary ridges in the skull are by no means so marked as in 

 the allied genera. 



One species, the Talapoin, C. talap)oin, has been separated into 

 a distinct genus, Miopithecus, on account of the fact that the 

 lower molars have only three tubercles instead of the usual four. 

 But if this be done, then Cercopithecus moloncyi, which has a 

 lower molar with five tubercles, should also be separated. 



The genus CercopifJiecas is limited to Africa, and its numerous 



Fig. 269. — Diana Monkey. Cercopithecus diana. x J. 



species have often a very limited range. They are frequently 

 rather brightly coloured, with blue and white patches on the face. 

 The Diana Monkey has a pointed white beardi Of the Vervet 

 Monkey {C lalandii) a curious fact was noticed at the Zoological 



