340 ELEMENTARY ZOOLOGY. 



the fields and the woods. Man cannot get back to nature 

 in an open-minded and appreciative way without being 

 the gainer. 



334. Definition of the Class. The birds are marked 

 by the fact that they are bipeds in which the skin develops 

 feathers, instead of scales or hair; the front appendages 

 are usually suited to flying. The jaws are covered with 

 a horny beak and do not bear teeth. They are warm- 

 blooded and lay the largest eggs found among animals. 



335. Practical Exercise. Identify, by means of keys in some 

 bird book, at least ten of the native species of birds. 



336. Key to the Principal Orders of Birds. 



Birds with no keel; incapable of flight . . Order Cur sores (runners) . 



Examples: Ostrich, rheas, emus, apteryx, cassowaries. 

 Keeled breast-bone; mostly flyers ....DIVISION CARINAT^:. 

 Toes united by web, or fringed with web, for swimming or 

 diving. 



All four toes in the web Order Steganopodes. 



Examples: Cormorants and pelicans. 

 Only three toes in the web. 



Feet far back ; wings short .... Order Pygopodes (divers) . 



Examples: Auks, penguins, loons, grebes. 

 Feet more forward; body heavy; wings broad, 



Order Anseres. 



Examples: Ducks, geese, swans, flamingo. 

 Feet more forward; long pointed wings, 



Order Longipennes (t ea-flyers) . 

 Examples: Gulls, tern, petrels, albatross. 



Toes only slightly if at all webbed ; long legs for wading ; neck 

 and beak long. 



Hind toe higher than the others. 



Larger birds Order Paludicolce (marsh birds) . 



Examples: Cranes, rails, mud-hens. 



Smaller birds Order Limicola? (shore-birds) . 



Examples: Snipe, woodcock, plovers, curlews, sand- 

 pipers. 



Hind toe not higher than others Order Herodines. 



Examples: Heron, ibis, bittern. 



