DUSKY GROUSE. 
479 
podes. The young in their first feathers are in all respects like 
the female, and the males do not acquire their full plumage 
until after the second moult. All moult twice a-year, and 
most of the Lagopodes change their colours with the seasons 
in a remarkable manner. 
The genus Tetrao is now composed of thirteen species, — 
three Lagopodes^ two Bonasice, and eight typical Tetraones, 
This enumeration does not include the Tetrao rupestris, which 
we do not consider well established, any more than the new 
species of Mr Brehm. The species of Lagopus^ as might be 
inferred from their inhabiting high northern latitudes, are com- 
mon to both continents, with the exception of the red grouse, 
T Scoticus, which is peculiar to the British islands, and which, 
from its not changing the colours of its plumage with the sea- 
sons, may be considered as forming the passage to the true 
Tetraones, Of these, there are five in North America, each and 
all distinct from the three European. Of the two Bonasice^ 
one is peculiar to the old, and the other to the new continent, 
the former having sixteen, the latter eighteen feathers to the 
tail. Thus the entire number is seven in Europe, while it is 
eight in North America. Setting aside the two common to 
both, and the respective Bonasice^ we may consider the cock 
of the woods of Europe as the parallel of the cock of the plains 
of America. The black grouse, T, tetrix^ will find its equiva- 
lent in the dusky grouse, T, obscurus ; but the T, hyhridus has 
no representative in America, any more than the T. Scoti- 
cus. These, however, are more than replaced as to number, 
by the T, phasianellus, T. cupido, and T, Canadensis^ all Ame- 
rican species, which have none corresponding to them in the 
old world. 
Perhaps no other naturalist has personally inspected all the 
known species of this genus of both continents, and having ex- 
amined numerous specimens even of some of the rarest, and 
possessing all but one in my own collection, my advantages 
are peculiar for giving a monography of this interesting genus. 
Such a work it is my intention hereafter to publish, illustrated 
