TETRAOXID.E: GROUSE. 735 



whitish and brtiwuish, uuraerously spotted and streaked on the head and rump with blackish. 

 A species of general dispersion in elevated and wooded, especially coniferous, regions of the 

 West; S. to New Mexico and Arizona; in the Rocky Mts. northerly shading into rich- 

 ardsoni in Montana and Idaho, westerly into fuliginosus. A large cumbrous bird, usually 

 displaying stolidity or indifference to the j)resence of man, taking to trees when disturbed, and 

 very easily slaughtered ; hence it is a "fool lien " in the idiom of the " wild and woolly West." 

 Besides buds, leaves, and various berries, this Grouse feeds much on insects. Kesideut wher- 

 ever found, breeding up to the timber-line ; the rumbling mating process with much noise and 

 fuss in spring: eggs laid in May and June. These are fewer in numl)er than those of Cana- 

 chites, generally 8 or 9, but from 7 to 10, or perhaps a dozen; larger, more elongated, and 

 less heavily colored than those of Spruce Grouse and Ptarmigan ; creamy-buff, finely freckled 

 all over with chocolate-brown, sekhjm with any large spots : 2.00 X 1.40. (Canace (Dendra- 

 gapus) obscura of previous eds. of the Key. D. obscurus A. 0. U.) 



D. o. rich'ardsoni. (To Sir John Richardson.) Richardson's Dusky Grouse. Size, 

 shape, and whole appearance of the foregoing. Tail rather longer, more nearly even, with 

 broader feathers, having the terminal slate bar reduced or wanting; general color more uni- 

 formly darker; black of throat more extensive. Rocky Mts., northerly, U. S. and northward. 

 It shades into obscurus proper in Idaho and Wyoming, into fuliginosus westward from this 

 region, but keeps its own characters N. to the limit of its range in the interior of British 

 America to about lat. 62°. (^Canace obscura richardsoni of previous eds. of the Key. D. ob- 

 scurus riclmrdsoni A. 0. U.) 



D. o. fuligiiio'sus. (Lat. fuliginosus, sooty.) Sooty Grouse. With less broad slate tail- 

 b;ir than obscurus proper, but colors darker than in richardsoni even. $ above, blackish, 

 minutely freckled with gray and rusty-brown; beh)w, dark plumbeous; usually no distinct 

 wliite markings on scapulars or flanks. The lien is more different, with prevailing rich rusty 

 and chestnut-brown markings. Northwest Coast mountains, California and Oregon to Sitka, 

 Alaska, E. in the interior till it shades into obscurus in Nevada and Idaho, and into richard- 

 soni in Idaho and British Columbia. Eggs indistinguishable from those of the foreiroinir, usu- 

 ally 8-10 in number, sometimes more, averaging 1.95 X l-S-i. (Canace obscura fuliginosa of 

 previous eds. of the Key. D. obscurus fuliginosus A. 0. U.) 



CENTROCER'CUS. (Gr. Kfvrpov, Jcentron, a spine, prickle; KtpKos, kerkos, tail.) Sage 

 Guor.sE. Spine-Tail Grouse. Of great size. Tail very long, equalling or exceeding the 

 wings, of l(t-20 stifiened, narrow, acuminate feathers, much graduated in length. Neck sus- 

 ceptible of enormous distention by means of air-sacs covered with naked livid skin — not regu- 

 larly hemispherical and lateral like those of Dendragapus and Tgmpanuchus, but forming a 

 great protuberance in front, of irregular contctur ; surmounted by a fringe of hair-like fila- 

 ments, several inches long, springing from a mass of erect white feathers; covered htlnw witii 

 a solid set of sharp white horny feathers, like fish-scales. (The affair is not easy to describe 

 in few words, especially as it is constantly changing with wear of tlie feathers, and is only 

 fully exhibited by the cock during the amours. The anatomical arrangement for intlition is 

 only a special exhibition of the air-sacs of other genera, as Dendragapus, 7'gmpanuchus, and 

 J'edicecetcs ; the peculiarities of tlie feathers are the inherited results of habitual attrition, the 

 l)irds rubbing tlie breast against tlie ground in their love-spasms ; and, as said, the state of the 

 ]iarts is always changing with wear of the feathers. This accounts for the vague or conflicting 

 statements of authors.) Tarsus feathered to toes. Digestive system remarkable for slight 

 muscularity of the gizzard, which is ratln-r a membranous paunch than a grist-mill ; the bin! 

 browses rather than .scrat<dies for a living, feeding on wormwood and also extensively on in- 

 sects. The food is by no means .so exclusive as some have supposed, includinj; many kinds of 

 berries and seeds, and sometimes consisting mainly of grasshoppers. Sexe.s similar in color, 

 unlike in size and to some extent in form. .Meat of breast dark. Kggs dark in ground ctdor, 

 imitoiMdy spotted. One prairie species, p»'rfectly terrestrial. 



