238 ALLEN'S NATURALIST'S LIBRARY. 



face. Hairs of forehead long and projecting anteriorly ; tail 

 one-quarter longer than the body ; hands generally entirely 

 lacking the thumbs, though sometimes a rudimentary thumb is 

 present, and that occasionally on one hand only. Naked portion 

 of tail covered with sensory papillae, rendering it more sensi- 

 tive, so it is said, than the hand. Length of body, 24 inches ; 

 tail, 30 inches. The skull in some specimens of the thumbed 

 variety is compressed laterally, and shows a sagittal crest 

 along the top. 



Distribution. This species is spread over Guiana, the forests 

 of the Ucayali and Huallaga rivers in eastern Peru, and the 

 northern part of Brazil, where it is known as the "Coaita," taking 

 the place of the more northern Ateks ater. " It occurs," says 

 Mr. Bates, " throughout the lowlands of the Lower and Upper 

 Amazons, but does not range to the south beyond the limits 

 of the river plains." In the higher part of the Rio Negro it 

 comes down to the north bank, but does not cross to the south 

 bank of the river. 



Habits. This species is the best known of all the Spider- 

 Monkeys. It is captured in large numbers, when young, by the 

 natives of Guiana, and as they bear captivity well, many of them 

 have been brought to Europe. They live in larger troops than 

 do some of the other members of its genus ; indeed, these com- 

 panies are said to number as many as a hundred. They are 

 very easily tamed, and become very affectionate. They live 

 chiefly on fruits, principally on a species of palm-nut. Dam- 

 pier, however, says, apparently of this species of Aides : " The 

 Monkeys come down by the Sea-side [at low water] and catch 

 them [the Periwinckles and Muscles] ; digging them out of 

 their Shells with their Claws." Large numbers of this species 



