1 82 ALLEN'S NATURALIST'S LIBRARY. 



" In the lower part of the river you will find on the north the 

 facchus {Hapale\ bicolor, and the Brachyurus couxui [Pithecia 

 satanas\, and on the south the red-whiskered Pithecia. Higher 

 up you will find on the north the A teles paniscus, and on the 

 south a black Jacchus and the Lagothrix humboldtii." 



THE SAKIS. GENUS PITHECIA. 

 Pithead, Geoffr., Ann. Mus., xix., p. 115 (1812). 

 Chiropotes, Gray, Cat. Monkeys Brit. Mus., p. 60 (1870), in 

 part. 



The Sakis form the second section of the present Sub-family, 

 and are characterised by their long, thick, and bushy non-pre- 

 hensile tail. A thick beard conceals the large chin. Hair on 

 the crown long, divided by a central line, and hanging over the 

 head, half concealing the pleasing diminutive face, or con- 

 fined to the head, cheeks, and chin. The ears are large. The 

 upper and lower incisor teeth project forward, the upper inner 

 pair being moderately large, the outer very small ; canines 

 strong and conical ; first pre-molar smaller than the others, and 

 one-cusped; molars with square crowns, grooved in the middle 

 and slightly four-cusped. 



In the brain the whole of the cerebellum and the olfactory 

 lobes are covered by the cerebrum. In general form the latter 

 resembles that of the species of Cebus. The frontal and oc- 

 cipital regions of the skull approximate in form to those in 

 Man ; the angle of the mandible is expanded, but less so than 

 among the Howlers (Mycetes). The ribs are relatively broader 

 in this genus than in any other of the American Monkeys. 



I. THE HAIRY SAKI. PITHECIA MONACHUS. 



Simla monachus, Humb. and Bonpl., Obs. Zool., p. 359 (1811). 



