Genus CANACE, Reichenbach.
Gen. Char. Bill smooth, with no lateral groove, depressed, or broader than high. Feathers of the head and neck all normal, i.e. no crest, nor lengthened plumes of any kind. Tail lengthened (i.e. nearly equal to wing), rounded, the feathers broad to the end; consisting of from sixteen to twenty feathers. Toes naked.
Subgenera.
Canace. Tail of sixteen feathers; no air-sac on side of the neck. Size small. (Type, T. canadensis, L.)
Dendragapus. Tail of twenty feathers; an inflatable air-sac on side of the neck. Size large. (Type, T. obscurus, Say.)
The American species of Wood Grouse appear, on comparison, to be generically distinct from Tetrao, of the Old World, (type, Tetrao urogallus,) and, moreover, are themselves comprised under two definable subgenera. Canace proper has a near relative in Falcipennis, Elliot, (type, Tetrao falcipennis, Hartlaub,) of Siberia, which differs merely in the attenuation of the primaries, and seems to us not separable from Canace. There is no European genus nearly related to our birds. T. urogallus differs very essentially in high, compressed, and light-colored bill, elongated and stiffened feathers of the whole head and neck, metallic colors, etc. T. (Lyrurus) tetrix approaches nearer in the bill, but also has metallic colors and a very peculiarly formed tail. Thus it seems absolutely necessary to adopt the name Canace, of Reichenbach, as a generic term by which to designate the American Wood Grouse.
Subgenus CANACE, Reichenbach.
Canace, Reichenbach, Av. Syst. Nat. 1851. (Type, Tetrao canadensis, L.)
Gen. Char. Tail of sixteen feathers, rounded, the feathers broad to the end. A colored (red or yellow) “comb” of naked skin over the eye. No inflatable air-sac on side of the neck. No crest, nor unusual plumes, about the head or neck.