Class 6. Mammalia. Order 14. Primates. 



533 



with easBj using all four limbs, the whole of the foot or hand resting 

 upon the ground. In Man alone the hind limbs exclusively are used, 

 and are very strongly developed for terrestrial locomotion. They are 

 almost all tropical animals, feeding principally upon fruit. 



Hallux capable of 

 considerable movement. 

 Hind limbs little or no 

 stronger than the fore. 



Hallux only capable 

 of slight movement. 

 Hind limbs extraordin- 

 arily well-developed. 



Platyrrhinse 



a t a r r h i n 86 

 Anthropidse 



Distance between the external 

 nares fairly large. External 

 auditory meatus unossified. A 

 small foramen in the septum 

 between the orbit and the tem- 

 poral fossa, p f . 



Distance between the nares 

 small. External auditory 

 meatus partially ossified. No 

 foramen in the septum between 

 the orbit and the temporal 

 fossa, p f . 



Sub-Order 1. PlatyrrhinsB. 



The external nares are separated by a broad membranous bridge. 

 Three premolars are present both above and below ; usual dental 

 formula : i |-, c -f, p f, to f. No portion of the external auditory 

 meatus ossified. In the posterior border of the jugal there is a tiny 

 perforation of the septum between the orbit and the temporal fossa, 

 i.e., the septum is not quite complete. Caecum relatively large. 

 Cheek-pouches and ischial callosities absent. Fore limbs usually 

 somewhat shorter than hind. Tail well developed, sometimes pre- 

 hensile. Confined to South and Central Am^erica. 



1. Sapajous or Capuchin Monkeys (Cebus) have a long tail covered with hau-, 

 and capable of being rolled up like a watch spring and coiled round bi'anches of 

 trees. In the Howling Monkeys (Mycetes) the tail is very powerful, its 

 tip is naked on the ventral side and sensory, and it is developed as an organ of 

 attachment (the animal can even hang by it alone), i.e., is a genuine prehensile 

 tail; the hyoid is large and hollowed out to receive an outgrowth of the larynx. 

 The Spider Monkeys {Ateles). with similar tails, are characterised by the 

 rudimentary nature or absence of the pollex. 



2. The Marmosets {Hapalidse) have a flattened naU. only on the hallux; 

 on all the other digits on the contraiy, the nails are so much arched as to be 

 claw-like. This small group may also be distinguished from other Platyrrhines 

 in that in | only are present. The tail is hairy, and cannot be coUed up ; the 

 pollex has but little power of independent movement. In other respects the 

 Hapalidse come near to the other PlatyiThines. 



Sub-Order 2. CatarrMnffi. 



The external nares are close together. Two premolars (dental 

 formula always : i ^, c \, 'p ^, m ^). Proximal portion of the 

 external auditory meatus ossified over a considerable extent. 



