BIRDS. 41 



Kk. Nostrils concealed by bristly feathers , tarsus scutellate 

 behind; hind claw long and nearly straight; inner 

 secondaries lengthened. . . . ALAUDID^E, 25. 



kKG. No crest; nostrils exposed; tarsus strictly &quot; oscine.&quot; 



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. . MOTACILLID^E, 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. . . VIREONID^, 31. 



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



hooked ; colors often brilliant. SYLVICOLID^E, 27. 



II. Clamatores. 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 primary lengthened, often longest, always more than f 



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. .... TYBANNID^:, 36. 



H, FAMILIES OF PICARI^E. 



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



of outer toe ; ( hallux wanting in Picoides.) 



a. Tail scansorial, of 12 rigid, acuminate feathers, of which the 

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

 nasal tufts usually developed. . . . PICID^E, 42. 



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

 curved; no nasal tufts CDCULID^E, 41. 



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



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



ALCEDINID.E, 40. 



III. Feet neither zygodactyle nor syndactyle; wings long and 

 pointed. 



