Xvi NORTH AMERICAN BIRDS. 



a. Cypseli. Palate segithognathous. Wings lengthened in their ter- 

 minal j)ortions, abbreviated Ijasall}', with the first primary not reduced. 

 Tail of ten rectrices. Bill fissirostral or tenuirostral. Feet never zygo- 

 dactyle nor syndactyle, small, weak, scarcely fitted for locomotion; 

 hallux often elevated or lateral or reversed ; front toes usually webbed 

 at base, or with abnormal ratio of phalanges in length and number, or 

 botli. Sternum deep-keeled, usually entire or else doubly notched or 

 perforate. Syringeal muscles not more than one pair. 

 h. Cuculi. Palate desmognathous. Wings not peculiar in brevity of 

 proximal or length of distal portions, and with first primary not reduced. 

 Tail of eight to twelve rectrices. Bill of indeterminate form, never 

 cered ; tongue not extensile. Feet variously modified by versatility 

 or reversion of either first, second, or fourth toes, or by cohesion for a 

 great distance of third and fourth, or by absence or rudimentary condi- 

 tion of first or second ; often highly scansorial, rarely amljulatorial. 

 Syringeal muscles two pairs at most. 



c. Pici. Palate " exhibiting a simplification and degradation of the 

 tegithognathous structure" (Huxley); wings bearing out this passerine 

 affinity in the common reduction of the first primary and the restriction 

 of the greater coverts. Tail of ten perfect rectrices and usually a sup- 

 plementary pair. Rostrum hard, straight, narrow, subequal to head, 

 with commonly extensile and vermiform but not furcate tongue. Feet 

 highly scansorial. Fourth toe permanently reversed ; basal phalanges 

 of toes abbreviated. Sternum doubly notched. Salivary glands highly 

 developed. Hyoidean apparatus peculiar. 

 C PSITTACI. Bill enormously thick, vshort, high, much arched from the 

 base, the upper mandible strongly hooked at the end, cered at base, and 

 freely movable by complete articulation with the forehead, the under man- 

 dible with short, broad, truncate symphysis. Feet permanently zygodactyle 

 by reversion of the fourth toe, which articulates by a double facet. Tarsi 

 reticulate. Syrinx peculiai-ly constructed of three pairs of intrinsic muscles. 

 Tongue short, thick,- fleshy. Sternum entire or fenestrate. Clavicles weak, 

 defective, or wanting. Orbit more or less completed by approach or union 

 of postorbital process and lachrymal. Altricial ; psiloptedic. 



D. RAPTORES. Bill usually powerful, adapted for tearing flesh, strongly 

 decurved and hooked at the end, furnished with a cere in which the nostrils 

 open. Feet strongly flexible, with large, sharp, much curved claws gradually 

 narrowed from base to tip, convex on the sides, that of the second toe larger 

 than that of the fourth toe, and the hinder not smaller than the second one. 

 Feet never permanently zygodactyle, though fourth toe often versatile ; an- 

 terior toes commonly with one basal Aveh; hallux considerable and com- 

 pletely incumbent (except CatharUdce). Legs feathered to the sufi'rago or 

 beyond. Rectrices twelve (with rare exceptions) ; primaries sinuate or 

 emarginate (with rare exceptions). Sternum singly or doubly notched or 

 fenestrate. Palate desmognathous. Carotids double. Syrinx wanting or 

 developed with only one pair of muscles. Altricial ; the young being weak 

 and helpless, yet ptilopjedic, being downy at birth. 



E. COLUMB^. Bill straight, compressed, horny at the vaulted tip, Avhich 

 is separated by a constriction from the soft membranous basal portion. Nos- 



of Picarice correspond respectively to the Cypselomorphce, Coccygomoiyhce, and Celcovwiyhcc of 

 Huxley, from wliom many of the characters are bon-owed. 



