200 CLASS MAMMALIA. 



approximation to the human form by which some of 

 them are so strikingly remarkable, exhibit a greater 

 elongation of muzzle, a tail, and a mode of loco- 

 motion more quadrupedal ; still however the freedom 

 of the arms, and the peculiar formation of the hands 

 in all of these animals, allow of their performing a 

 number of actions and gesticulations similar to 

 those of man. 



These animals have for a long time been divided 

 into two genera, monkeys and lemurs, which by 

 the multiplication of secondary forms have become 

 two small families. Between these a third genus, 

 that of the Ouistitis *, may be placed, as the species 

 included in it cannot conveniently be referred to 

 either of the others. 



THE MONKEYS, {Simia, Linnaeus). 



These include all such quadrumanous animals as 

 have four straight incisive teeth in each jaw, and flat 

 nails on all the extremities, two characters which 

 approximate them more closely to the human form 

 than the genera which follow. Their cheek teeth, 

 also, like ours have only blunt tubercles, and they 

 live naturally upon fruits : but their canine teeth, 

 being longer than the others, supply them with a 

 weapon of which we are destitute, and require a 

 vacuum in the opposite jaw to receive them when 

 the mouth is closed. 



* Hapales Illiger, very small American monkeys, with nails, 

 pointed, arched, and compressed laterally. — Ed. 



