DISTRIBUTION OF MONKEYS AND LEMURS 229 



Section IV. — Distribution of New World Monkeys 



The Cebidte, or Platyrrhine Monkeys, which we will now 

 consider, are not so numerous as their cousins of the Old 

 World, only from fifty to sixty species being usually 

 recognized, although many of these are not very perfectly 

 distinguished. They are also confined to much narrower 

 limits than the monkeys of the Old World, being entirely 

 restricted to the warmer portions of the Neotropical region, 

 and, being purely arboreal in their habits, to those parts of 

 it which are covered by dense forests. Their northern 

 limit is Guatemala and the adjacent districts of Southern 

 Mexico, the most northern locality for monkeys in the 

 New World positively ascertained being about 23° N. lat., 

 in the State of San Louis Potosi. This, it may be observed, 

 is in striking contrast to the northern range of the Quadru- 

 mana of the Old World, which, as has been shown, extends 

 to 41° N. lat. To the west of the Andes of South America 

 monkeys are only found as far south as the Gulf of 

 Guayaquil, the arid and treeless nature of the whole 

 southern portion of the west coast being quite unsuitable 

 for forest-loving animals. To the east of the Andes, how- 

 ever, monkeys extend all over the vast forests of the 

 valleys of the Orinoco and Amazon and as far south as the 

 wooded districts of Paraguay and the adjoining provinces 

 of the Argentine Republic. Burmeister includes three 

 species of Cebidoe in his list of the mammals of the La 

 Plata States. 



The New World Monkeys are usually divided into 

 about nine genera, amongst which the Spider-Monkeys, 

 (Ateles) occupy the highest position. The Spider-Monkeys 



