150 ALLEN'S NATURALISTS LIBRARY. 



reach. The expression of countenance in these small Mon- 

 keys is intelligent and pleasing. This is partly owing to the 

 open facial angle, which is given as one of 60, but the quick 

 movements of the head, and the way they have of inclining 

 it on one side, when their curiosity is excited, contribute very 

 much to give them a knowing expression. ... In mobility 

 of expression of countenance, intelligence and general manners> 

 these small Monkeys resemble the higher Apes far more than 

 they do any rodent animal with which I am acquainted, not- 

 withstanding their apparently low organisation in many 

 points." 



This description of the habits of the Negro Tamarin may 

 be taken as representative of those of the various species of 

 the genus, of whom only glimpses can be caught in their homes, 

 which are the safe altitudes of the giants of the virgin forests 

 of Brazil. \ 



THE CAPUCHINS, HOWLERS, AND SPIDER- 

 MONKEYS, &c. FAMILY CEBID.E. 



This family embraces the typical Platyrrhine Monkeys, and to 

 it belongs the great majority of the American species. As 

 already pointed out (p. 127) their nose is flat, and the partition 

 between the nostrils, which open sideways, is very broad, and 

 separates them widely. They are essentially quadrupedal, and 

 walk with the soles of both pairs of limbs flat to the ground. 

 The Spider-Monkeys occasionally, however, assume an erect 

 posture. " They all possess tails, and in some genera (e.g., 

 Ateles) this organ becomes very flexible and muscular, and the 

 under surface of its curled extremity is devoid of hair and 

 highly sensitive. The tail thus modified is a powerful pre- 

 hensile organ and serves for a fifth hand." (Huxley.} In these 



