THE ANIMAL KINGDOM 21 



hind-foot. Thumb and great toe are not completely opposable to the 

 other digits. The uterus is two-horned. 



Sub-order Anthropoidea. Anthropoids include the remainder of the 

 primates. Hands and feet are differentiated, and either the thumb or the 

 great toe is opposable. Finger and toe-nails are flat, except in the marmo- 

 sets which have claws. 



VOUNG CHIMPANZEE. _ 



Pig. 24.— Young chimpanzee, a type of anthropoid. (From photograph by Fred 



Johnson.) 



Three chief sections of anthropoids are recognized : 



Platyrhina. The South American monkeys, with broad nasal septum, 

 three premolar teeth in each half-iaw (except the marmosets which, like 

 the Old World monkeys, have two), and a cUmbing foot. 



Catarrhina. The Old World monkeys and the great apes, with a 

 narrow nasal septum, two premolar teeth in each half jaw, and a climbing 

 foot. 



Bimana. Also with narrow nasal septum and two premolars, but 

 with the great toe non-opposable and a walking foot. 



