XVII OUAKARI MONKEYS 561 
species Bb. rubicundus at any rate has an absolutely as well as 
a relatively greater length of intestines and caecum than any 
other American Monkey known. 
Not the least remarkable fact about these Ouakari Monkeys is 
their distribution in South America. We cannot do better than 
ne 
Fie. 267.—White-nosed Saki. Pithecia albinasa. xt. (From Nature.) 
quote the summary given by Messrs. P. L, and W. L, Sclater in 
their Geography of Mammals, which is as follows: “Each of 
them, as first shown by Bates and afterwards further explained 
by Forbes, is limited to a comparatively small tract of forest on 
the banks of the Amazon and its affluents. The Black-headed 
Ouakari (B. melanocephalus) . . . is met with only in a tract 
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