SUBFAMILY TETRAONINA. 203 
KEY TO THE SPECIES. 
A. Under parts of adult male, mostly black. 
a. Upper tail-coverts narrowly tipped with t CANADA GROUSE. 
grayish white. C. canadensis. 
pure white. CRUSE: 
6. Upper tail-coverts broadly tipped with BENS 
C. frank line. 
GENUS TYMPANUCHUS 
(Latin Zympanum, a drum; +nucha, neck). 
Tympanuchus, Gloger. Gemeinutzig, Hand- und Hilfsbuch, 
Naturg., 1842, p. 396. Type, 7etrao cupido, Linn. 
Air sacs on sides of neck, above which arise tufts of winglike, 
lengthened, more or less acuminated, feathers. Head crested. 
Tarsi rather scantily feathered to the toes, the latter webbed at 
base. ‘Tail short, rounded, consisting of eighteen feathers. Size 
large, sexes similar. 
The Prairie Hens are divided into three species and one sub- 
species, constituting a well-marked and distinct group of the sub- 
family, with characteristics that easily give them recognition 
among their allies. They are essentially birds of the plains, 
although they do not hesitate to perch upon the limbs of trees, 
fences, or any support that may be most convenient at the time. 
They go usually in coveys, generally consisting of a single family, 
but in the autumn are accustomed to gather in enormous packs 
and then are very difficult of approach. Formerly abundant 
over much of eastern North America, they are now confined to 
the prairie countries of the west and south, and the island of 
Martha’s Vineyard on the eastern coast. Throughout their dis- 
persion there is little or no difference in the habits of the various 
races. 
KEY TO THE SPECIES. 
A. Winglike tufts of feathers on the sides of 
neck, 
a. Neck tufts pointed. Size large. 
a. Scapulars without conspicuous white PRAIRIE HEN. 
terminal spot. Neck tufts very long. T. americanus. 
