THE UAKARI MONKEYS 



181 



fers from the preceding by the hair of the body and the limbs being of an almost 

 uniform rich, deep chestnut hue, only becoming rather paler on the neck. This is 

 in marked contrast to the pale sandy white, tending slightly to rufous, on the 

 under parts and the inner surfaces of the limbs, characteristic of the baldheaded 

 uakari. Both species agree, however, in their brilliant scarlet faces, and in having 

 hair of a rich chestnut tint beneath the throat ; and there can be no doubt but 

 that the} r are extremely closely related, and have acquired their slight differences 

 of coloration by being now completely separated from one another, although de- 

 scended at no very distinct epoch from a common ancestor. 



Black-Headed 

 Uakari 



THE BI,ACK-HEADED UAKARI. 



The most northerly representative of these monkeys is the black- 

 headed uakari (U. melanocephala) , which is found in the forests to 

 the north of the Rio Negro, especially on the Cassiquiare and the Rio 

 Branco. It thus enters the basins of both the Amazon and the Orinoco, so that it 

 has a considerably larger distributional area than either of the other species, from 

 both of which it is widely different in coloration. 



The general color is blackish, but the back and sides of the body are yellowish, 

 while the loins, the outer surface of the thighs, and the tip of the tail are reddish 

 chestnut ; the face, hands, and feet being completely black. 



