DISTRIBUTION OF MONKEYS AND LEMURS 



231 



Saki are all inhabitants of various localities within this 

 district. The mode of distribution of the three species 

 of Ouakari is still more remarkable. 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), as shown by 

 the accompanying map (prepared by Forbes), which we 



Map of the Specific Aeeas of the Ouakaris. 



(P. Z. S. 1880, p. 647.) 



have been kindly permitted to use by the Zoological 

 Society of London, is met with only in a tract traversed 

 by the Rio Negro, the Bald-headed Ouakari appears to 

 be confined to the triangle formed by the union of the 

 Amazon with another affluent, the Japura, and the Red 

 Ouakari to the forests on the north bank of the Amazon 

 opposite Olivenca, and lying between the main stream and 

 the river lea. Each of them evidently takes the place 

 of the others in its particular district. Of this peculiar 



