TETRAONIDM. 



185 



e\ Tail more than two-thirds as long as wing; bill small and 

 weak, its depth at base less than length of middle claw. 



Callipepla. (Page 191.) 



el Tail less than two-thirds as long as wing ; bill stouter, its 



depth at base decidedly greater than length of middle 



claw. 



p. Head with a conspicuous crest of long narrow feathers 



exceeding tarsus in length ; plumage of upper parts 



plain olive ; wing more than 5.00. 



Oreortyx. (Page 190.) 

 p. Head not conspicuously crested, or else with longest 

 feathers much shorter than tarsus ; plumage of upper 

 parts much varied with spots, bars, and other mark- 

 ings; wing less than 5.00. 

 g^. Head not distinctly crested... Colinus. (Page 186.) 



g"^. Head distinctly crested Eiipsychortyx} 



c*. Tail much less than half as long as wing, the feathers soft, narrow at 

 tips, and hardly distinguishable from the coverts ; claws very large, 

 broad, and blunt, the middle one nearly as long as the exj^osed culmen. 

 Head with a full soft crest of blended feathers ; sexes exceed- 

 ingly different in colors , Cyrtonyx. (Page 193.) 



At least upper half of tarsus feathered (usually feathered to toes) ; nasal fossaj 

 densely feathered ; sides of toes pectinated in winter (the points deciduous in 

 summer) ; lai'ger (wing more than 6.00). (Subfamily Tetraonince.) 

 ¥. Legs feathered down to base of. toes. 



cl Tail longer than wingSj graduated, the feathers narrow and pointed ; 



wing more than 10.00 Centrocercus. (Page 204.) 



&. Tail shorter than wings, not graduated (or else extremely short, with 

 middle pair of feathers longer than rest), the feathers broad and 

 rounded, or nearly truncated, at tips ; wing less than 10.00. 

 d}. Tail about half as long as wing, graduated or much rounded. 



e\ Tail graduated, with middle pair of feathers projecting much 

 beyond the rest ; no tufts or other elongated feathers on 



neck Pediocaetes. (Page 203.) 



el Tail rounded, middle pair of feathers not projecting beyond 

 rest ; sides of neck with a conspicuous tuft of straight, 

 rather stiff feathers, and beneath these an inflatable air-sac. 



Tympanuchus. (Page 202.) 



<P. Tail more than half as long as wing, rounded or nearly even ; no 



tufts, ruffs, or other conspicuous feathers on neck. 



e'. Toes feathered; tail less than two-thirds as long as wing; 



plumage becoming chiefly or entirely pure white in 



winter Lagopus. (Page 198.) 



1 Eupsychortyx Gould, Mod. Odont. 1S50, 15. Type, Tetrao cn'status Linn. 



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