AVES. 213 



modern investigations is outlined by Stejneger in the Standard 

 Natural History. The following largely artificial key to the 

 Orders recognized by the Am. Orn. Assoc. is partly arranged from 

 the key given by Kidgway (Man. N. Am. Birds). 



Orders of Aves. 

 A. STERNUM KEELED: 



a. Feet totipalmate, the hind toe well developed and all four toes full-webbed ; 

 palate desmognathous ......... STEGANOPODES, XXXIV. 



aa. Feet not totipalmate, the hind toe, if present, not connected with the 



others. 



6. Feet palmate, the anterior toes full-webbed or nearly so (or lobate, with 

 the claws broad, nail-like) (tarsus not specially elongate, and the tibia 

 little if any naked below, in our species). 

 c. Bill not lamellate, its cutting edge entire ; schizognathous. ( Cecomor- 



phce Huxley, Stejneger.) 



d. Legs inserted far behind the middle of the body, which in standing 

 position is more or less erect ...... PYGOPODES, XXXI. 



dd. Legs not inserted far behind the middle of the body, which in a 

 standing position has its axis nearly horizontal; wings usually 

 very long. 

 e. Nostrils not tubular ........ LONGIPENNES, XXXII. 



ee. Nostrils tubular ......... TUBINARES, XXXIII. 



cc. Bill lamellate, its cutting edges serrated or fringed. 



ANSERES, XXXV. 



bb. Feet not palmate (with rare exceptions), the toes cleft, or webbed at 

 base or on sides (full-webbed only in a few waders, with very long 

 tarsus and the tibia partly naked). 



f. Waders, tibia usually more or less naked below; the tarsus more 



or less elongate. 



g. Hind toes well developed and usually inserted on same level 

 as anterior toes, the claws never excessiveh' lengthened; 

 loral or orbital regions or both naked; desmognathous. 



HERODIONES, XXXVI. 



gg. Hind toe, if present, small and inserted above level of the 

 the rest (or else size moderate). L. less than 36 inches; the 

 loral and orbital regions feathered, the middle claw not pec- 

 tinate); schizognathous. (Grallae.) 



h. Hind toe short and elevated (or if the bird is less than 

 3 feet long, the hind toe almost on the level of anterior 

 toes) ......... PALUDICOL^:, XXXVII. 



hh. Hind toe (if present) short and distinctly elevated (length 

 never more than 2 feet). . . LIMICOL^E, XXXVIII. 

 jy. Not waders; tibia mostly entirely feathered; tarsus not greatly 

 elongate. 



f. Bill strongly hooked, with a distinct cere at base; 



desmognathous. 



/. Toes 3 in front; 1 behind, the outer toe sometimes 

 reversible ....... RAPTORES, XLT. 



jj. Toes 2 in front; 2 behind, the outer toe perma- 

 nently reversed ...... PSITTACI, XLII. 



