APES, MONKEYS, AND LEMURS. 27 



The last group of the family is formed by the uakari and saki monkeys, 

 which constitute a sub-family distinguished from all the foregoing by the 

 lower incisor teeth being inclined obliquely forward, some- 

 what after the manner of those of the lemurs, and separated Uakaris 

 by an interval from the canines. The tail, which may be (Uacaria). 

 either long or short, is never prehensile, and the thumb is well 

 developed. Usually the nostrils are widely separated, and the ears are large. 



The uakaris, of which there are three species, each with a very small dis- 

 tributional area, are readily distinguished from all other American monkeys 

 by the extreme shortness of the tail. The bald uakari (Uacaria calva) from 

 the Rio Negro, and the red uakari (U. rubicunda] from the Upper Amazon, 

 have a brilliant scarlet face, contrasting strongly with the long silky white 

 hair of the body, whereas the black-faced species ( U. melanocephala) has a 

 dark countenance. All are timid, gentle creatures, of so delicate a constitu- 

 tion that it is almost impossible to keep them in confinement. 



The sakis, of which there are five species, are readily distinguished from 

 the last by the long bushy tail and the thick beard adorn- 

 ing the chin. In the lower jaw the angle is expanded in a Sakis 

 manner approaching that of the howlers. A familiar type (Pithecia). 

 is the black saki (Pithecia satanus) of the Lower Amazon ; 

 and while in some species, like the hairy saki (P. monacJtus), long hair clothes 

 the he;id, body, and tail, in others this is confined to the region of the head. 

 In habits these monkeys appear to be very similar to the vakaris. 



The beautiful and delicate little creatures from Tropical America, commonly 

 known as marmosets, form a family agreeing in many respects with the last, 

 but distinguished by having only two pairs of molar teeth in 

 each jaw, and also by the fingers and toes, with the excep- The Marmosets, 

 tion of the shortened great-toe, terminating in carved com- Family 

 pressed claws, instead of flattened nails. The long thumb Hapalidw. 

 lies parallel to the other digits, to which it is incapable of 

 being opposed, so that the fore-limb terminates in a paw rather than a hand. 

 The skin of the face is naked, the ears are large 

 and frequently surmounted by a fringe of long 

 hairs, and the long and bushy tail has no prehen- 

 sile power. The family, which is represented by 

 a large number of species, mostly inhabitants of 

 the forests of Equatorial South America, has been 

 divided into two genera according to the length 

 of the lower canine teeth. Those forms in which 

 these teeth are not longer than the incisors are 

 known as true marmosets (Hapale\ whereas those 

 in which the former considerably exceed the 

 latter have been termed tamarins (Midas). Mar- 

 mosets vary considerably in colour, some having 

 "the fur mottled with grey, brown, and black, 

 whereas in others it has a more or less uniformly 

 golden or silvery tint. Marmosets are essentially Fi 3- 14 ;~ A MARMOSET 



forest animals, feeding chiefly on insects and 



fruit, and are so delicate that it is difficult to keep them alive out of the 

 tropics. They are exceedingly gentle in disposition, and soon become 

 tame and affectionate. In. their organisation they are the lowest of the 

 monkey tribe. 



