ORDERS OF MAMMALIA. 317 



present. In one single instance ( Colobus) the thumbs of the 

 fore-limbs are wanting. 



FIG. 159. Quadrumana. Green Monkey (Cercocebus salceus). (After Cuvier.) 



With the single exception of a Monkey which occurs on 

 the Rock of Gibraltar, all the Catarhine Monkeys are confined 

 to Africa and Asia. The most typical forms of the section are 

 the Semnopitheci and Macaques of Asia. Less typical are 

 the Baboons, which inhabit Africa, and are among the most re- 

 pulsive of all the Quadrumana. In these the tail is always 

 short, and often quite rudimentary. The head is large, and 

 the muzzle greatly prolonged, having the nostrils at its ex- 

 tremity. More than any other of the Monkeys they employ 

 the fore-limbs in terrestrial progression, running upon all fours 

 with the greatest ease. 



The third family of the Catarhine Monkeys is that of the 

 Anthropoid Apes, so called from their making a nearer ap- 

 proach to man in anatomical structure than is the case with 

 any other Mammal. The Anthropoid Apes are distinguished 

 by having no tail, nor cheek-pouches. The hind-limbs are 

 short shorter than the fore-limbs and the animal can pro- 

 gress in an erect or semi-erect posture. At the same time the 

 hind-feet are strictly prehensile, since the thumbs are oppos- 



