BIRDS. 41 



AA;. Nostrils concealed by bristly feathers; tarsus scutellate 

 behind; hind claw long and nearly straight; inner 

 secondaries lengthened. .. . . AiAUDiDiB, 35. 



kkh. No crest; nostrils exposed; tarsus strictly "oscine." 



I. Hind claw much elongated, twice as long as middle claw, 



with its toe much longer than middle toe and claw ; 

 bill very slender; longest secondary nearly equal to 

 primaries in closed wing. . MoTACiLLlDiB, 26. 



II. Hind claw not specially elongated, not twice as long as 



middle claw ; inner secondaries not lengthened. 



m. Bill stout, compressed, notched, and abruptly hooked 



at tip; general color olivaceous, tail not blotched 



with white or yellow. . . VrRBONiD.a!, 31. 



mm. Bill various, notched or not, but little, if at all, 



hooked ; colors often brilliant. STLVicoiiiD^, 37. 



II. Olamatores. Outside of tarsus covered with a series of plates 



variously arranged, lapping entirely around in front and 



behind to meet in a groove on the inner side ; primaries 10. 



n. First primaiy lengthened, often longest, always more than t 



length of the longest; bill broad, depressed, tapering to a 



point which is abruptly hooked ; rictal bristles numerous ; 



nostrils overhung but not concealed ; tail not tipped with 



yellow. .... TYBAKNiDiB, 36. 



H. FAMILIES OF PICARI^. 



I. Feet zygodactyle (two toes in front, two behind) by reversion 



of outer toe ; ( hallux wanting in Picoides.) 



a. Tail scansorial, of 13 rigid, acuminate feathers, of which the 

 outer pair are short and concealed ; bill stout and straight ; 

 nasal tufts usually developed. . . . Picid^, 43. 



aa. Tail not scansorial, of 8 to 10 long, soft feathers ; bill de- 

 curved ; no nasal tufts CacnLiD^, 41. 



II. Feet syndactyle, by cohesion of outer and middle toes ; tibiae 



naked below; bill stout and straight, longer than head. 



AliCEDIOTD^, 40. 



III. Feet neither zygodactyle nor syndaclyle; wings long and 

 pointed. 



