176 APES, MONKEYS, AND LEMURS 



by the record of the two which have been exhibited of late years in the London 

 Zoological Gardens, one of which was received on the fifteenth of May, 1866, and 

 died on the twenty-sixth of the following June. 



The last representative of this group of sakis is the Brazilian 

 whiskered saki (P. rufiventer], which is distinguished, among other 

 features, by the hairs being marked by a yellowish ring near the end. 

 It is also characterized in the adult state by the red color of the under parts, as well 

 as by the forehead being of the same grayish-black color as the body. The mous- 

 tache is yellow. 



In the young of this species the moustache is white, while the under parts of 

 the body are gray. 



THE RED-BACKED SAKI (Pithetia chiropotes} 



With the red-backed saki, which was first obtained by Humboldt on the banks 

 of the Orinoco, and also occurs in Guiana, we come to the first of another group of 

 the genus, distinguished in several points from all the species yet described. 



In the first place, the hair of the head, although radiating from a central point, 

 in the young, in the adult is divided by a median parting, and falls down on either 

 side. Then the long beard is divided, by a gap in the middle of the chin, into two 

 lateral moieties, while the fur on the body, instead of being long and harsh, is short 

 and soft. The tail also has shorter hair than in the last group, and is thick and 

 club-shaped. Finally, the hinder part of the lower jawbone is more expanded than 

 in the typical group. The peculiar form of the neatly-divided and flattened hair 

 of the head gives these animals the appearance of wearing a wig. 



The general color of the fur in this saki is blackish brown, but there is a con- 

 siderable area on the back and shoulders of a yellowish-red tint, from which the 

 species derives its name. The tail is very thick and bushy, and the beard greatly 

 developed. 



Humboldt describes the red-backed saki as " a robust, active, fierce, and un-' 

 tamable animal ; when irritated it raises itself on the hinder extremities, grinds its 

 teeth, rubs the end of the beard violently, and darts upon the person who has 

 excited its displeasure. In confinement, it is habitually melancholy, and is never 

 excited to gaiety, except at the moment of receiving its favorite food. It seldom 

 drinks, but when it does so the operation is performed in a peculiar manner. Thus, 

 instead of putting its lips, after the manner of other monkeys, to the water or the 

 vessel containing it, this species conveys it to its mouth in the hollow of the hand, 

 at the same time bending forward its head. It is not, however, easy to witness this 

 singular trait of character, since the animal is unwilling to satisfy its thirst when 

 watched or likely to be observed." In their wild state the same traveler relates 

 that these animals live only in pairs. Their voice, which is but seldom heard, is 

 described as a kind of disagreeable grunt. 



Closely allied to the preceding species is the one represented in the 



figure on the following page (P. satanas} , which is an inhabitant of 



Brazil. It is readily distinguished by the absence of the yellowish red on the back 



