DUSKY GROUSE. 373 
suit them for scratching away the snow covering the vegetables 
which compose their food. The wings of the grouse are short 
and rounded ; the first primary is shorter than the third and 
fourth, which are longest. The tail is usually composed of © 
eighteen feathers, generally broad and rounded. The red 
crouse, 7’. Scoticus, however, and the European Bonasiv, and 
T. Canadensis, or spotted grouse, have but sixteen ; while our 
two new North American species have twenty, one of them 
having these feathers very narrow and pointed, the narrowness 
being also observed in the sharp-tailed grouse. They have 
the head small, the neck short, and the body massive and 
very fleshy. 
The females of the larger species differ greatly from the 
males, which are glossy black or blackish, while the former 
are mottled with grey, blackish, and rufous: such are all the 
typical Zetraones of Europe, and the cock of the plains, the 
dusky and the spotted grouse of America. ‘T’he smaller species, 
in which both sexes are mottled, such as 7. phasianellus and 
T. Cupido, exhibit little or no difference in the plumage of the 
two sexes; which is also the case in all the Bonasie and 
Lagopodes. 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 Bonasie, and eight typical Tetraones. 
This enumeration does not include the T'etrao 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 
common to both continents, with the exception of the red 
grouse, 7. Scoticus, which is peculiar to the British islands, 
and which, from its not changing the colours of its plumage 
with the seasons, may be considered as forming the passage 
to the true Zetraones. Of these, there are five in North 
