TETRAONID. 185 
ée. 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.) 
e. Tail less than two-thirds as long as wing; bill stouter, its 
depth at base decidedly greater than length of middle 
claw. 
j}. 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.) 
Jf*?. 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.........ccceceeeeeee Eupsychortyx. 
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 exposed culmen. 
Head with a full soft crest of blended feathers; sexes exceed- 
ingly different in colors....... ie Cyrtonyx. (Page 193.) 
a. At least upper half of tarsus feathered (usually feathered to toes); nasal fossa 
densely feathered ; sides of toes pectinated in winter (the points deciduous in 
summer); larger (wing more than 6.00). (Subfamily Tetraonine.) 
b'. Legs feathered down to base of toes. 
c. Tail longer than wings, graduated, the feathers narrow and pointed ; 
wing more than 10.00 .......:.scseseeeeees Centrocercus. (Page 204.) 
c. 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. 
é. Tail graduated, with middle pair,of feathers projecting much 
beyond the rest; no tufts or other elongated feathers on 
NECK. ..racceccocsenssenscesssenerserseee Pediocztes. (Page 203.) 
é. 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.) 
d@. Tail more than half as long as wing, rounded or nearly even; no 
tufts, ruffs, or other conspicuous feathers on neck. 
é. Toes feathered; tail less than two-thirds as long as wing; 
plumage becoming chiefly or entirely pure white in 
WinteYr.......00 UcnlonunetelsGadudewsonasigs Lagopus. (Page 198.) 
1 Eupsychortyx GouLp, Mon. Odont. 1850, 15. Type, Tetrao cristatus Linn. 
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