DUSKY GROUSE. 
475 
ters, but even in their peculiar habits, that he might, with 
almost the same propriety, have included in it all typical gal- 
linaceous birds. Latham very judiciously separated the genus 
Tinamus, as well as that of Perdix, which latter he restored 
from Brisson. Illiger likewise contributed to our better know- 
ledge of these birds, by characterising two more natural genera, 
Syrrhaptes and Ortygis, Temminck, in his Histoire des Galli- 
nacts^ carried the number to seven, but has since reduced it by 
reuniting Coturnix to Perdix, 
The true Tetraones are divided by Vieillot into two genera, 
the Lagopodes forming a distinct one by themselves. These, 
however, we regard as no more than a subgenus, of which we 
distinguish three in our genus Tetrao, I. Lagopus^ which re- 
presents it in the Arctic Polar regions ; for whose climate they 
are admirably adapted by being clothed to the very nails in 
plumage suited to the temperature, furnished abundantly with 
thick down, upon which the feathers are closely applied. The 
colour of their winter plumage is an additional protection 
against rapacious animals, by rendering it difficult to distin- 
guish them from the snows by which they are surrounded. 
II. Tetrao^ which is distributed over the more temperate cli- 
mates ; the legs being still feathered down to the toes. III. 
Bonasia^ a new division, of which we propose Tetrao bonasia^ 
L. as the type, in which only the upper portion of the tarsus 
is feathered. These occasionally descend still farther south 
than the others, inhabiting wooded plains as well as mountain- 
ous regions, to which those of the second section are more par- 
ticularly attached. But the entire genus is exclusively boreal, 
being only found in Europe, and the northern countries of 
America and Asia. The long and sharp-winged grouse, or 
Pterqcles of Temminck, which represent, or rather replace 
these birds in the arid and sandy countries of Africa and Asia, 
a single species inhabiting also the southern extremity of 
Europe, we consider, in common with all modern authors, as 
a totally distinct genus. That group, composed of but few 
species, resort to the most desert regions, preferring dry and 
burning wastes to the cool shelter of the woods. These oceans, 
