QUADRUMANA. 555 



common Marmoset (Hapale penidllata]^ but several species are 

 domesticated and kept as pets. 



Fam. 2. Cebidce. In this family are all the typical Platyrhine 

 Monkeys, in which the dentition differs from that of the Hap- 

 alidcz in having an additional molar, so that the molars are the 

 same as in the Catarhina and in Man, but the praemolars are 

 more numerous. The dental formula is 



. 

 2-2' i i 33 3-3 



There are neither cheek-pouches nor " callosities ;" and the 

 face is usually more or less naked, though sometimes whis- 

 kered. The tail is long, and is mostly prehensile ; though in 

 rare instances it is non-prehensile, and has its extremity clothed 

 with hairs. The thumb of the fore-hand may be wanting, and, 

 if present, is not opposable. All the fingers are furnished with 

 flat nails. Their diet is miscellaneous, consisting partly of in- 

 sects and partly of fruit. 



The Cebidce are exclusively confined to the warmer parts of 

 South America, in the vast forests of which they are met with 

 in large troops, climbing amongst the trees. The Spider 

 Monkeys (Ateles), the Howling MSnkeys (Mycetes), the Ca- 

 puchin Monkey ( Cebus), and the Squirrel Monkey ( Callithrix\ 

 may serve as typical examples of this section of the Quadru- 

 mana. 



CATARHINA. 



The third and highest section of the Quadrumana is that of 

 the Catarhina or Old World Monkeys. In this section the 

 nostrils are oblique, and are placed close together, and the 

 septum narium is narrow. The thumbs of all the feet are 

 opposable, so that the animal is strictly quadrumanous. In 

 Colobus alone the anterior thumbs (pollex) are wanting. The 

 dental formula is the same as in man, viz. : 



2 2 I I 22 33 



The incisors, however, are projecting and prominent, and 

 the canines especially in the males are large and pointed. 

 Moreover, the teeth form an uneven series, interrupted by a 

 diastema or interval. The tail is never prehensile, and is 

 sometimes absent. Cheek-pouches are often present, and the 

 skin covering the tubera ischii is almost always callous and 

 destitute of hair, constituting the so-called " natal callosities." 

 With the single exception of a Monkey which inhabits the 



