7 6 



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 



