Its general colour is a black brown, with narrow bars of pale ocraceous; plumage near the base of the beak above tinged with ferruginous; each feather on the head, with a single band and slight tip, those of the neck, back, tail coverts, and breast, two bands and tip, the tips on the upper part of the back and on the tail coverts are broad and spotted with black, with the inferior band often obsolete; the throat and inferior portion of the upper sides of the neck are covered with whitish feathers, on each of which is a black band or spot; a white band on each feather of the breast, becoming broader on those nearer the belly; on the belly, the plumage is dull cinereous with concealed white lines on the shafts; {203} the wing coverts and scapulars, about two banded with a spotted tip and second band, and with the tip of the shaft white; the primaries and secondaries have whitish zigzag spots on their outer webs, the first feather of the former short, the second longer, the third, fourth, and fifth equal, longest feathers of the sides with two or three bands and white spot at the tip of the shaft; inferior tail coverts, white with a black band and base, and slightly tinged with ocraceous on their centres; legs feathered to the toes, and with the thighs pale, undulated with dusky; tail rounded with a broad terminal band of cinereous, on which are black zigzag spots; on the intermediate feathers are several ocraceous spotted bands, but these become obsolete and confined to the exterior webs on the lateral feathers, until they are hardly perceptible on the exterior pair; a naked space above and beneath the eyes. It may be distinguished by the name of the Dusky Grouse (tetrao obscurus, S.). When this bird flew, it uttered a cackling note a little like that of the domestic fowl; this note was noticed by Lewis and Clarke in the bird which they speak of under the name of the cock of the plains, and to which Mr. Ord has applied the name of tetrao fusca; a bird which, agreeably to their description, appears to be different from this, having the legs only half booted; the "fleshy protuberance about the base of the upper chop," and "the long pointed tail" of that bird may possibly be sexual distinctions. It appears by the observations of Lewis and Clarke, that several species of this genus inhabit the country which they traversed, particularly in this elevated range of mountains, from whence, amongst other interesting animals, they brought to Philadelphia a specimen of the spotted grouse (T. canadensis); which, together with the above described bird, are now preserved in the Philadelphia Museum, thus proving that the spotted grouse is an inhabitant of a portion of the territory of the United States. {204} In the evening, a thunder-storm rose in the east. It appeared for some time to approach, the thunder being loud and frequent, but at length moved off towards the south-east, continuing visible in the horizon during great part of the night.