206 LECTURE VIII. 



body is long and slender^ the limbs powerful, the eyes small, 

 the muzzle short, the head roundish, so that among all 

 American apes they most resemble man — a resemblance which 

 is increased by their having around the face tufts of hair 

 resembling whiskers and beard. It is only the flat nose which 

 mars the human likeness. The four hands are equally deve- 

 loped, the hand itself is long and narrow, but the thumb of the 

 posterior hand is longer and stronger than that of the anterior. 

 The dental system consists of four chisel-shaped incisors, two 

 large projecting and somewhat curved canine teeth, presenting 

 deep grooves on the inner side, and twelve molars in each jaw, 

 so that the number of teeth amounts to thirty-six. The molars 

 diminish in breadth backwards, so that the hindmost is small 

 and almost rudimentary compared with the other. 



We shall first examine the external aspect. The brown 

 Cebus reaches to the size of a cat, and presents in middle age 

 a yellowish brown colour, somewhat brighter on the belly, 

 whilst the vertex, the cheeks, forearm, hands and legs are dark 

 brown or black. The face has a tinge of violet, the eyebrows 

 are long, on the short forehead is brown hair so stifi" that the 

 animal seems on a side view to be provided with two horns. 

 The ear is covered with long soft hair ; the beard is of a paler 

 shade. 



The Cebus albifrons was met with by Humboldt near the 

 cataracts of the Oiinoco, and is by most zoologists considered 

 a mere variety of the Capuchin monkey. The face is bluish 

 grey, forehead and eyemargins white, the body dark grey on 

 the back, of a lighter shade on the thorax and belly, the limbs 

 yellowish- white, the vertex brownish -grey, so that the animal 

 seems to wear a cap on the head. The ears are very hairy. 

 The common Capuchin monkey, to which this variety is said 

 to belong, greatly resembles the Cebus as regards colour. 



The skull presents in both species exactly the same shape. 

 Viewed from above, we see an elongated oval, having its 

 greatest breadth in the posterior part corresponding to the 

 large occipital foramen. We must here certainly make allow- 

 ance for the projection of the mastoid processes, the upper brims 

 of which are continuations of those of the zygomatic arches. 



