vn MONKEYS— AFFINITIES AND DISTRIBUTION 155 



themselves, riding a bicycle, and many others, while they 

 even learn to count up to three or four. 



The long-tailed monkeys of Africa are very numerous 

 and varied. One group (Colobus) has no cheek-pouches 

 and no thumb on the hand, and many of these have long 

 soft fur of varied colours. The most numerous group are 



f ^ 



Fia. 27.— PLUTO MONKEY (Cevcopithecus Pluto). 



the Guenons, belonging to the genus Cercopithecus, rather 

 small long-tailed monkeys, very active and lively, and 

 often having their faces curiously marked with white or 

 black, or ornamented with whiskers or other tufts of hair, 

 as well shown in the Pluto monkey here figured (Fig. 27). 

 They all have large cheek-pouches and good-sized thumbs. 

 Many of them are called green monkeys, from the greenish- 



