232 TETRAONIDE, GROUSE, PARTRIDGES.—GEN. 178. 
mexicana GouLD, Proc. Zool. Soc. 1856, 61; Bp., 618; Extioz, pl. 38; 
Coor:, 523. GALLOPAVO. 
Var. aAmeRICANA Bant., Tray. 1791, 290. Gallopavo sylvestris Le Conte, Proce. 
Phila. Acad. 1857,179; MM. gallopavo Aup., v, 42, pls. 287, 288 ; Nurt.,i,630; Bp., 
615. Upper tail coverts without light tips, and ends of tail feathers scarcely paler. 
This is the ordinary wild turkey of Eastern North America; N. to Canada, where 
it is said still to occur; apparently extirpated in New England. N.W. to the 
Missouri, and $.W. to Texas (Audubon). The slight. differences just noted seem to 
be remarkably constant, and to be rarely, if ever, shown by the other form, although, 
as usual in domestic birds, this last varies interminably in color. 
Family TETRAONID4. Grouse, ete. 
All the remaining gallinaceous birds are very closely related, and they will prob- 
ably constitute a single family, although the term Tetraonide is usually restricted 
to the true grouse as below defined ( Tetraonine), the partridges being erected into 
another family, Perdicide, with several subfamilies. But the grouse do not appear 
to differ more from the partridges than these do from each other, and they are all — 
variously interrelated; so that no violence will be offered in uniting them. One 
group of the partridges is confined to America; all the rest to the Old World. The 
leading forms among the latter are Perdiz, the true partridge; Cotwrnix, the true 
quail; Francolinus, the francolins; with Rollulus and Caccabis. In all, perhaps 
a hundred species and a dozen genera. Without attempting to frame a family 
diagnosis to cover all their modifications, I will precisely define the American forms, 
as two subfamilies. 
Subfamily TETRAONINA. Grouse. 
Head completely feathered, excepting, usually, a naked strip of skin over the 
eye. Nasal fossze densely feathered. Tarsi more or less perfectly feathered, the 
feathering sometimes extending on the toes to the claws ; the toes, when naked, with 
fringe-like processes. Tail variable in shape, but never folded, of 16-20 feathers. 
Sides of the neck frequently with lengthened or otherwise modified feathers, or a 
bare distensible skin, or both. ; 
The true grouse are confined to the northern hemisphere, and reach their highest 
development, asa group, in North America, where singularly varied forms occur. 
The only Old World species are—the great Tetrao urogallus, or capercailzie of 
Europe, and its allied Asiatic species; Tetrao tetrix, the ‘‘ black game” of Europe, 
with curiously curled tail feathers; Tetrao falcipennis of Siberia, the represen- 
tative of our spruce partridge ; Bonasa betulina of Northern Europe and Asia, like 
our ruffed grouse; and two or three species of ptarmigan (Lagopus). 
178. Genus TETRAO Linneeus. 
*.* No peculiar feathers on the neck; tarsus feathered to the toes; tail mod- 
erate, little rounded, of 16-20 broad feathers. Woodland birds of northerly or 
alpine distribution. Our species differ materially from the European capercailzie, 
T. urogallus, type of the genus, and might be properly separated. 
* Tail normally of 16 (14-18) feathers. (Can«ace.) 
Canada Grouse. Spruce Partridge. . g below mostly black with 
numerous white spots; above, vermiculated with blackish and slate, and 
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