258 Birds of Colorado 



b' Head not crested. 



a* Inner secondaries elongated, nearly as long as the 



longer primaries ; hind claw straight, equal to or 



exceeding the hind toe. Motacillidae, p. 472. 



b* Inner secondaries not elongated, hind claw curved, 



always clearly shorter than the hind toe. 



Mniotiltidae, p. 438. 

 b* Bill short, stout, deep and conical. 



a' Bill notched at the tip and with bristles at the gape, 

 a* Nostrils more or less concealed by bristles or overhung 

 by a distinct scale, or the cutting-edge of the lower 

 mandible forming a distinct angle. 



Fringillidse, p. 319. 

 b* Nostrils exposed ; cutting-edge of the lower mandible 

 always straight and without any angle. 



Tangaridse, p. 408. 



b^ Bill without notch at the tip, or bristles at the gape. 



Icteridae, p. 299. 

 1». Primaries obviously ten ; the outer one more or less shortened, 

 a^ Tarsus distinctly scutellate in front. 



a* Outer primary at least half as long as the next. 



a' Bill distinctly hooked at the tip. Laniidae, p. 427. 



b^ Bill not distinctly hooked at the tip. 



a* Nasal plumes erect or inclined backwards, 

 a^ Rictal bristles well developed. 



Mimidae (except Oroscoptes), p. 477. 



b^ No rictal bristles. Troglodytidse, p. 485. 



b* Nasal bristles directed forwards and nostrils con- 

 cealed. Corvidae, p. 282. 



l>* Outer primary not half as long as the next, generally 

 much shorter. 

 a' BiU shghtly hooked or notched at the tip. 

 a* Smaller ; wing under 2-5. 



a* Above greenish or greyish ; tail even. 



Vireonidae, p. 431. 

 b^ Above bluish, tail graduated. 



Sylviidae (Polioptila), p. 509. 

 b* Larger, wing over 3-5. 



Mimidae (Oroscoptes), p. 477. 

 b* Bill not hooked or notched. 



a* Tail-feathers stiff and pointed at tip. 



Certhiidae, p. 496. 



