BIRDS. 37 



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



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



Bill lengthened, not cered. . . 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. 

 6. 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 soi't, swollen 



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



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



short. Humming-birds. . . PICARL&:, fl. 



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 Avide 

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

 cc. Bill lengthened, not fissirostral. 

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



second. LIMICOLJE, M. 



dd. First primary not emarginate, 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 semipahnate ; two or three of them joined at base only 



by evident movable webbing. 

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

 /. Tibia? 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. 



