232 TETRAONID^, GROUSE, PARTRIDGES. GEN. 178. 



mexicana Gould, Proc. Zool. Soc. 1856, 61; Bd., 618; Elliot, pi. 38; 

 Coop., 523 gallopavo. 



; ^ -^ Var. AMERICANA Baet., Trav. 1791, 290. Gallopavo sylvestris Le Conte, Proc. 

 Phila. Acad. 1857, 179 ; M. gallopavo Aud., v, 42, pis. 287, 288 ; Nutt., i, 630 ; Bd., 

 G15. Upper tail coverts without light tips, and ends of tail feathers scarcely paler. 

 This is tlie 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 S.W. to Texas (Auduhon). The slight differences just noted seem to 

 be remarlvabljr constant, and to be rarely, if ever, shown by tlie other form, although, 

 as usual in domestic birds, this last varies interminably in color. 



Family TETRAOETID-ffl. Grouse, etc. 



All the remaining gallinaceous birds are very closelj^ related, and they will prob- 

 ablj' constitute a single familj'^, although the term Tetraonidce is usually restricted 

 to the true grouse as below defined ( Tetraonince) , the partridges being erected into 

 another famil}^, Perdicidai, 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 

 variouslj' interrelated ; so that no violence will be offered in uniting them. One 

 gi-oup of the partridges is confined to America ; all the rest to the Old World. The 

 leading forms among the latter are Perdix, the true partridge ; Coturni-x, the true 

 quail ; Francoliniis, the francolins ; with PoIIuhis and C'accabis. 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 TETRAONINJE. Grouse. 



Head completely feathered, excepting, usually, a naked strip of skin over the 

 eye. Nasal fossa3 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, as a group, in North America, where singularly varied forms occur. 

 The only Old World species are — the great Tetrao wro(/rtifos, or capercailzie of 

 Europe, and its allied Asiatic species; Tetrao tetrix, the "black game" of Europe, 

 with curiously curled tail feathers ; Tetrao faldpennis 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 Linnseus. 



*.;^*No peculiar feathers on the neck; tarsus feathered to the toes; tail mod- 

 orate, little rounded, of 16-20 broad feathers. Woodland birds of northerly or 

 alpine distribution. Our species differ matcrialljr from the European capercailzie, 

 T. urogallus, type of the genus, and might be properly separated. 



* Tail normally of 16 (14-18) feathers. {Canace.) 



Canada Grouse. Spruce Partrkhje. $ below mostly black with 

 mimcrous white spots ; above, vermiciilatcd with blackish and slate, and 



