BIRDS. 37 



*** Toes 4 : two in front, two behind. 



Bill cered and hooked. . . . PSITTACI, I. 



Bill lengthened, not cered nor hooked. PICARLE, H. 

 **** Toes 4 : three in front, one behind. 



I. Toes not webbed at all, cleft to the base, or with the basal 



joints immovably coherent. 



a. Hind toe inserted on a level with the. rest and generally 

 longer than the shortest anterior toe. 



b. Claw of hind toe at least as long as that of middle toe. 



f Bill without cere, never very strongly hooked; outer 



toe not versatile PASSERES, G. 



ff Bill with cere, strongly hooked; outer toe usually 

 versatile ; claws very sharp and strong. RAPTORES, J. 

 bb. Claw of hind toe shorter than that of middle toe. 

 \ Bill stoutish ; nostrils opening beneath a soft, swollen 

 membrane (shrunken in drying). COLUMB.E, K. 

 \\ Bill tenuirostral, very slender; secondaries 6, very 

 short. Humming-birds. . . PICARLE, H. 

 aa. Hind toe elevated above the level of the rest, and usually 

 shorter than the others. 



c. Bill fissirostral culmen very short, but gape very wide 



and deep, reaching to below eyes. . PICARLE, H. 

 cc. Bill lengthened, not fissirostral. 

 d. First primary emarginate, or else about as long as 



second. LIMICOL<E, M. 



dd. First primary not emarginate, much shorter than 

 second ALECTORIDES, O. 



II. Toes syndactyle without webbing, but with the outer and 



middle toes coherent half their length. . PICARLE, H. 



III. Toes semipalmate; two or three of them joined at base only 

 by evident movable webbing. 



e. Hind toe inserted on a level with the rest. 

 f. Tibia3 feathered below. 

 g. Bill cered and hooked ; claws sharp and strong. 



RAPTORES, J. 



gg. Bill not cered and hooked ; nostrils opening beneath 

 a soft, swollen membrane. . . COLUMB^E, K. 



