712 MAMMALIA [CH. 



on each side of each jaw, the largest number found amongst 

 Anthropoidea. The Cebidae have prehensile tails which assist 

 .them in climbing. The genus Ateles includes the Spider-monkeys, 

 in which this function of the tail is prominent, the under side of 

 this organ being naked and scaly so as to allow the animal to 

 obtain a hold. The genus Cebus has the tail hairy all round; 

 several species of this genus are often seen in captivity. 



The CERCOPITHECIDAE and SIMIIDAE are confined to the Old 

 World. They constitute the section CATARRHINI, characterised 

 by the possession of a narrow internasal septum, a spout-like 

 prolongation of the tympanic bone extending into the base of the 

 ear-flap, and the reduction of the number of premolar teeth to two 

 pairs, whilst there are always three pairs of molars. The CER- 

 COPITHECIDAE have the legs as long as the arms, or longer, and go 

 habitually on all-fours. There are always bare patches of thick 

 callous skin on the buttocks forming the so-called ischial callosities, 

 on which the animals rest when they assume a sitting posture, 

 and there is in almost every case a well-developed tail. This family 

 includes the Indian and African monkeys, among them the Bandar- 

 log of Kipling's Jungle Tales. One species, Macacus inuus, the 

 Barbary ape, is found on the Rock of Gibraltar, and this is the only 

 species which enters Europe. It is remarkable for being completely 

 tailless. Semnopithecus entellus is the sacred Langur of India, and 

 owing to its immunity from persecution has become very abundant. 



The SIMIIDAE include those Monkeys which in structure and 

 appearance most resemble Man. In this family the tail is completely 

 absent, the arms are longer than the legs, and the gait might be 

 described as that of a baby learning to walk. They never go 

 completely on all-fours, but usually shuffle along unsteadily on 

 their two feet, which like those of a baby show a tendency to 

 turn inwards under them; they usually steady themselves by 

 bending forward so that their knuckles touch the ground. Four 

 genera are included in this section, viz. Hylobates, Simia, Gorilla 

 and Anthropopithecus. Hylobates include several species known 

 as Gibbons, inhabiting South-Eastern Asia and the Malay Archi- 

 pelago. These are Apes with exceedingly long arms; they assume 

 a completely upright position when on the ground and run along 

 holding up their long arms in the air as if they were balancing 

 poles. In their power of supporting themselves without resting the 

 arms on the ground they approach Man ; but in other respects they 

 depart widely from him, as for instance in the brain, where the 



