316 VERTEBRATE ANIMALS. 



Section A. Strepsirhina. Characterized by having the 

 nostrils twisted or curved, and placed at the end of the nose, 

 while the second toe of the hind-feet is furnished with a claw. 

 The Quadrumana of this section are chiefly referable to Mada- 

 gascar as their geographical centre, but they spread from 

 Madagascar westward into Africa, and eastward to the Indian 

 Archipelago. In this family are the Aye- Aye (Cheiromys), 

 the Loris and Slow Lemurs (Nycticebidoe), and the Lemurs 

 (Lemuridce). The Aye- Aye is confined to Madagascar, and is 

 not unlike a large squirrel in appearance, having a long bushy 

 tail. The incisors grow from permanent pulps, like those of 

 Rodents, and there are no canines. The Loris and Slow Le- 

 murs have either no tail or a rudimentary one, and they are 

 confined to Southern Asia, and the great islands of the Indian 

 Archipelago. The true Lemurs are natives of Madagascar, 

 and are often spoken of as "Madagascar cats." They have a 

 soft, woolly fur, and a long tail, which is prehensile. The sec- 

 ond toe of the hind-foot has a long and pointed claw. 



Section J3. Platyrhina. This section includes those mon- 

 keys in which the nostrils are simple, and are placed far apart ; 

 the thumbs of the fore-feet are wanting, or, if present, are not 

 opposable ; and the tail is generally prehensile. The Platy- 

 rhine Monkeys are exclusively confined to South America, oc- 

 curring especially in Brazil, and they are all adapted for a more 

 or less purely arboreal life. The best-known members of this 

 section are the Marmosets (Ifapalidce), and the great family 

 of the Gebidce, comprising the Spider-monkeys, the Howlers, 

 and others. The Howlers (Mycetes) are remarkable for having 

 a bony drum at the summit of the windpipe, by which the 

 voice is rendered extraordinarily resonant, and peculiarly weird 

 and terrifying to those who hear it. 



Section C. Catarhina. In this, the highest section of the 

 Quadrumana, the nostrils are oblique and placed close to- 

 gether, and the thumbs of all the feet are opposable, so that 

 they are truly " quadrumanous." The dental formula agrees 

 with that of man : 



.22 11 22 33 



The incisor teeth, however, are prominent and projecting, 

 and the canines, especially in the males, are large and pointed, 

 while the teeth form an uneven series. The tail is never pre- 

 hensile, and is sometimes absent. Cheek-pouches are often 



