10 THE BIRDS OF THE AIR. 



According to the Linnean system, which, 

 however, I shall not rigidly follow in my ar- 

 rangement, the Land Birds are divided into 

 four classes ; the Rapacious Birds (accipitres) ; 

 the Pies (pics)) ; the Passerine Birds (passeres) ; 

 and the Gallinaceous Birds (galling) : the Wa- 

 ter Birds consist of two classes, the Waders 

 (grallse) ; and the Swimmers (anseres). Of the 

 Rapacious Birds, the bills are hooked, and 

 there is an angular projection on the upper 

 mandible ; of the Pies, they are sharp-edged, 

 compressed on the sides, and convex on the 

 upper surface ; of the Passerine Birds, conical 

 and sharp pointed ; of the Gallinaceous Birds, 

 the upper mandible is considerably arched ; 

 the Waders have a roundish bill, and a fleshy 

 tongue ; and of the Swimmers, the bills are 

 broad at the top, and covered with a mem- 

 branaceous skin. 



