422 NORTH AMERICAN BIRDS. 



B. Tail nearly even, and without any terminal lighter band, or else having it 



badly defined. 



Colors, in other respects, of var. ohscurus, but cheeks, etc., less 

 dusky. Hab. Rocky Mountains of British America, south to the 

 Yellowstone and Hellgate region of United States (where grading 

 into var. ohscurus) ...... var. r ic hard so n i. 



Canace obscurus, var. obscurus, Say. 



DUSKY GROUSE. 



Tetrao ohscurus, Say, Long's Exped. E. Mts. II, 1823, 14. — Bon. Mon. Tetrno, Am. Phil. 

 Trans. Ill, 1830, 391. — Ib. Am. Orn. 111,1830, pi. xviii. — Baird, Birds N. Am. 

 1858, 620. — ScL. P. Z. S. 1858, 1. — Gi!AY, Cat. Brit. Mus. V, 1867, 86. — Coop. 

 Orn. Cal. I, 1870, 526 (in part). Canace obscura, Bonap. Comptes Kendus, XLV, 

 1857, 428. Dcndragajms obscurus, Elliot, P. A. N. S. 1864, 23. — Ib. Monog. 

 Tetraon. pi. 



Sp. Char. Male (19,161, Deer Creek, Neb., Feb. 13 ; G. II. Trook.) Ground-color 

 above slaty-black, but this almost completely overlaid by a minute, transverse mottling 



Canace obscurus. 



of bluish-ash, — pale brown on scapulars and secondaries, — mostly on terminal portion 

 of the feathers. Scapulars with a conspicuous shaft-streak and terminal spot of white. 

 Terminal band of tail sharply and abruptly defined, pure pale bluish-ash. and 1.50 inches 

 in width. Tail slightly rounded (about .80). Lower parts fine bluish-ashy, becoming 

 lighter posteriorly, more plumbeous anteriorly. On the sides of the jugulum the feathers 

 snowy-white beneath the surface, and this much exposed, producing a somewhat broken 

 but con.spicuous patch. Throat Avhite, with transverse crescentic bars of dusky; this 

 barred Avhite curving upward to the auriculars, behind a uniformly blackish malar patch ; 

 lores and post-ocular region with distinct white spots, producing an inconspicuous stripe 

 from the bill tin-ough the eye. All the feathers of the lower parts margined terminally 

 with Avhite, this growing broader on the flanks and erissum, the former of which have a 

 more brownish and mottled ground, and broad white shaft-stripes. Lining of wing 

 almost wholly white. Tarsi ashy-white. Length, 21.00 ; wing, 10.00 ; tail, 8.00 ; tarsus, 

 1.80 ; middle toe, 1.80. 



