CHAPTER V 

 APES, MONKEYS, AND LEMURS continued 



THE AMERICAN MONKEYS 

 Family CEBID^E 



The monkeys of America differ so remarkably from those of the Old World, 

 that they cannot be included in either of the families treated of in the two preceding 

 chapters. The true monkeys of the New World form, indeed, a perfectly distinct 

 family by themselves, known to zoologists as the Cebidtz. In addition to these, 

 there is another group of American Primates known as the marmosets, which, 

 although nearly related to the Cebidcs, constitute a second family, which will be 

 treated of in the next chapter. 



Not only is this distinction between the monkeys of the Eastern and Western 

 Hemispheres a feature characteristic of the present state of the world's history, but, 

 so far as we know, it was the case throughout geological history, for not a trace of 

 a New World monkey has been found in any of the formations of the Old World, 

 while those of the New World have yielded remains of species allied to those now 

 inhabiting the same regions. We have thus decisive evidence that both these 

 groups are of great antiquity ; and it has even been suggested that they have taken 

 their respective origins from animals probably allied to the lemurs quite independ- 

 ently of one another. 



For a long period zoologists were accustomed to class the apes, monkeys, and 

 baboons of the Old World in one group, to which they applied the name of narrow- 

 nosed monkeys (Catarhini}, from the circumstance that the partition between the 

 nostrils is a thin one ; while the American monkeys and marmosets, owing to the 

 width of this partition, were grouped together as broad-nosed monkeys (PUtiyrksnf). 

 Although there is a certain amount of convenience in this arrangement, it has now, 

 by common consent, been pretty generally abandoned, and the whole of the 

 Primates, exclusive of the lemurs, are divided simply into four families, of which 

 two belong to the Old World and two to the New. In the present chapter we shall 

 take into consideration only the true monkeys (Cebida) of the New World, the 

 better known representatives of which are popularly designated howlers, spider- 

 monkeys, sapajous, and titis as it is to these alone that the term American 

 monkeys should be restricted. 



Proceeding to notice the characteristics by which these animals 



cs are distinguished from their distant cousins of the Old World, we 



have to mention, in the first place, that no New World monkey has naked 



callosities on the buttocks. This characteristic will at once serve to distinguish 



(H3) 



