OBDER I. PERCHING BIRDS 49 



C. Nostrils not tubular but slit-like. (D.) 

 D. Upper mandible decidedly hooked at tip and plainly made up of 

 separate pieces, one forming a kind of roof to the nostrils ; i^ tail 



dark-colored, with the middle feathers lengthened LXI. Jaegers. 



D. Upper mandible not made up of separate pieces and at least as long 



as the lower mandible LX. Gulls, etc. 



D. Bill flattened sideways and knife-like ; the lower mandible' longer 



than the upper one i' LI X. Skimmers. 



E. Bill straight or slightly curved. (G.) 



E. Upper mandible decidedly hooked at tip, hawk-like." (F.) 

 F. Tail, 14-20 long and forked for half its length ; space in front of eyes 



bare of feathers '^ LI. Man-o'-War Birds. 



F. Tail, 5-10 long ; bill less than 4 ; plumage dark. LIII. Cormorants. 



F. Tail, 5-8 long; bill 8-15 long ; plumage light LII. Pelicans. 



G. Bill stout at base and slightly curved near tip ; is wing, 14-22 long. 



LV. Gannets. 



G. Bill slender and nearly straight ; wing, 12-14 long ; neck very 



long LIV. Darters. 



G. Bill stout, slightly curved ; wing, 10-12 long. . .LVI. Tropic Birds. 



ORDER I. PERCHING BIRDS (PASSERES) 



This is the highest and much the largest order of birds ; 

 it contains nearly half of our birds (those east of the 

 Rocky Mountains in the United States) and more than 

 half of all known birds. In it are found the finest of the 

 songsters. 



The toes are four in number, three in front and one behind. 

 The front toes are divided about to their bases and have no 

 webbing or membrane along their sides. The hind toe is on a 

 level with the rest and as long as the shortest front toe. The 

 legs are slender, comparatively short, and so placed as to give 

 the body, when at rest, a horizontal position. In size these 

 birds range from very small to medium; from the size of a 

 kinglet to that of a robin, or a little larger. 



12 13 



apgar's birds. — 4 



