76 CHARACTERS OF VERTEBRATE ANIMALS 



swellings on the face, and the large bare projections on the hinder 

 regions are blue and red. The Yellow Baboon {Papio babuin) of 

 West Africa is handsome by comparison with the two last species. 

 (2) New World Monkeys are a stage lower in development 

 than those of the Old World, and consequently less human in 

 appearance and structure. They always possess a tail, which 

 is commonly used as a grasping organ, and may also serve as 



Fig 45 ~ Red Howling Monkeys {Mycetes seniculus] 



a delicate organ of touch. The total number of permanent teeth 

 is thirty-six, four more than in Man and the Old World apes, 

 the excess being due to the presence of an extra premolar on 

 each side of each jaw. There is also a difference in the nose, 

 which has nostrils facing somewhat sideways, and separated by 

 a broad partition. 



Three distinct sections are recognized: — Naked-tailed Mon- 

 keys, Sajous, and Sakis. 



In the Naked-tailed Monkeys, at least part of the long and 

 powerful tail is devoid of hair on the under side, and is used as 

 a tactile and grasping organ. Among the noisiest of these forms 

 are the Howlers of South America, such, for example, as the Red 

 Howler {Mycetes seniculus) (fig. 45), in which the vocal organs are 



