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. Nostrils opening beneath a soft, swollen membrane ; head 



small ; tarsus reticulate behind. . COLUMB^E, K. 

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



RAPTOKES, J. 



bbb. Secondaries very short, six in number ; bill very slender ; 



smallest of all birds. . . . PICARLE, H. 



bbbb. Claw of hind toe as long or longer than that of middle 



toe; wing coverts in about two series, not reaching 



half way to tips of secondaries; musical apparatus 



more or less highly developed. . PASSERES, G. 



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. . . . . . ALJECTORIDES, 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. Tibiae 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. . . COLUMBJE, K. 



