WT 



300 



GAAf£ lilRDS OF NORTH AMERICA. 





tcT and unsavory, caused by tlic particular leaves on 

 which the birds feed. The American species, according 

 to my views, are divided into seven genera and twenty- 

 five species and subspecies. 



KEY TO THE GENERA. 

 A. Legs feathered wholly, or in part. 



a. Lejjs bare from the heel downward. 



b. Le>(s feathered to the toes. 

 a' . Tail scjuare at tip. 



a" . Tail feathers 20. Air sacs present. 



b" . Tail feathers 16. Air sacs absent. 



b' . Tail rounded of 18 rather stiff featiiers. 

 Tufts of lengthened feathers over air 

 sacs. 



c' . Tail pointed, of 18 soft feathers, cen- 

 tral pair longest. No tufts over air 

 sacs. 



d' , Tail pointed, stiff, of 20 fihimentous 

 feathers. Breast feathers hair-like. 



B. Legs and toes covered with feathers. 



RUFFED OROUSE. 



lionasa. 

 Page 74. 



DUSKY GROUSE. 



Dendragapus. 



\ _ 



) Page go. 



! SPRUCE (IROUSE. 

 Cattachiles. 

 Page 1 00. 



Si'kAIRIF. HENS. 

 Tympanuchus. 

 Page no. 



SHARP-TAILED 

 GROUSE. 



Pedicecetes. 

 Page 123. 



COCK-OF-TnE 

 PLAINS. 



Centrocerctts. 

 r ige 136. 



PTARMIGAN. 



Lagopus. 

 Page 142. 



GENUS nONASA 



(Greek povatra, Latin bopiasus, a bison. The bird's drumming 

 resembles a bison's bellow). 



Bonasa. Steph. Gen. Zool., vol. xi., 1819, p. 298. Type Tetrao 

 umbellus, Linn. 



Head crested, rudimentary air sac covered by a tuft of broad, 

 soft, glossy feathers. Tail broad, long, rounded, fan-shaped. 



