organ. 



CHARACTERS OF VERTEBRATE ANIMALS 



Lastly, in the Sakis the tail is not modified as a grasping 

 Examples are the Black Saki (Pithecia Satanas], with 

 bushy tail and ample beard, found in the basins of the Orinoco 

 and Amazons, and the Squirrel Monkey (Chrysothrix sciurea) 

 of Guiana. 



(3) The Marmosets or Clawed Monkeys of America are the 

 lowest and least intelligent forms to which the name " monkey " 



Fig. 47. The Ouistiti or Common Marmoset (HaJ>ale Jacckus] 



can properly be applied. These small creatures, of which the 

 Common Marmoset (Hapale Jacchus] may be taken as type 

 (fig. 47), have claws on all the digits except the great toe, which 

 is provided with a flat tail, and is opposable. The thumb, unlike 

 that of an ordinary monkey, is non-opposable. The teeth are 

 thirty-two in number, as in Man and the Old World forms, but 

 the dental formula is different, for whereas these possess eight 



