SAKI MONKEYS. 
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the forehead being of the same greyish-black colour as the body. The moustache 
is yellow. 
In the young of this species the moustache is white, while the under-parts of 
the body are grey. 
The Red-Backed Saki (Pithecia 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. 
THE BLACK SAKI (t liat. size). 
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 colour of the fur in this saki is blackish-brown, but there is a 
considerable area on the back and shoulders of a yellowish-red tint, from which the 
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