CHORDATA 409 



tats, which arc associated with structural differences as well. 

 The former arc also called the broad-nosed monkeys, since the 

 nasal septum is so broad that the nostrils arc directed outward 

 rather than forward. The number and also the arrangement of 

 the teeth is constant, and may be represented by the following 

 dental formula, indicating the teeth in one half of each jaw : in- 

 cisors |, canines {, premolars f, molars |. The tail is sometimes 

 longer, sometimes shorter, than the body and is often very useful 

 as a prehensile organ. The fur of some of these monkeys is 

 soft and silky and has considerable commercial value ; in other 

 cases it is coarse. The flesh of many is eaten by the natives of 

 South America. The largest of the New World monkeys is the 

 black howler, whose body is some seventy centimeters long ; all of 

 the howlers have resonance chambers in the throat by means of 

 which they produce their piercing cries. The spicier monkeys 

 (Fig. 391) are so called because of their slender bodies, long 

 legs, and very long, prehensile tails ; they are common in Brazil 

 and Central America. 



The Old World monkeys have a narrow nasal septum, so 

 that the nostrils lie close together and are directed forward 

 instead of outward. Their dental formula is constant, being in- 

 cisors f , canines -\, premolars §, molars |, which is the same as 

 that of man. Their digits are always provided with nails, never 

 with claws, and portions of the body are often destitute of hair - 

 the skin in such regions being brilliantly colored, often red, blue, 

 or green. The tail may be long or entirely absent, and is never 

 prehensile as in the New World monkeys. Further, their brain 

 is more highly developed and they are usually larger. They 

 live for the most part in tropical Africa and Asia. Here belongs 

 the common baboon of Africa, Cynocephalus babuin, with a body a 

 meter long and a tail half as long ; another species of the same 

 genus is the mandrill, whose tail is only about two centimeters 

 long ; the adult is very conspicuous, because of the bright red 

 and blue skin on its fore and hind quarters. The macaques of 

 India and the Pacific islands are, like many New World monkeys, 

 common in menageries. Many species of small monkeys 

 inhabit Africa and display the most varied colors; a striking 

 example is the green monkey, whose coat is of an olive-green 

 color. 



