620 



U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



TETRAO, Linnaeus. 



Tetrao, Linnaeus, Sj/st. Nat. 1744. Type T. urogallus, L. (Gra,y.) 



Ch. — ^Tail lengthened, slightly narrowed to the square or somewhat rounded tip ; about two-thirds the wing ; the feathers with 

 stiffened shafts. Tarsus feathered to and between the bases of the toes. No unusual feathers on the side of throat. Culmen 

 between the nasal fossae nearly half the total length. Color mostly black. 



Inhabit wooded regions. 



The American wood-grouse do not belong strictly to the genus Telrao, as defined by later 

 ■writers, with T. urogallus for type. This species difiers chiefly in the pointed feathers of the 

 chin, but in other respects comes quite close to T. obscurus. A genus, Canace, has been made 

 for the American birds, but I see no special occasion to adopt it here. 



The following diagnosis will distinguish the species : 



Tail of twenty feathers. General color plumbeous above, with fine mottling. Chin and 

 throat white and black. Tail uniform black, with slaty tip .....T. obscurus. 



Tail of sixteen feathers. Above banded with plumbeous. Beneath black, with some white 

 on jugulum and sides of belly. Tail tipped with brownish orange. Upper coverts not tipped 

 with white T. canadensis. 



Similar to last. Tail without orange tip. Upper tail coverts banded terminally with 

 white T.franklini. 



* Very poor specimen. 



TETRAO OBSCURUS, Say. 



Dusky Gronse. 



Tetrao obscurus, Sat, Long's EKped. R. Mts. II, 1823, 14.— Bon. Syn. 1828, 127.— Ib. Mon. Tetrao, Am. Phil. Trans. 

 Ill, 1830, 391.— Ib. Am. Dm. Ill, 1830 ; pl.xviii.— Sw. F. Bor. Am. II, 1831, 344 ; pi. lix, Ix.— 

 NnTTALL, Man. I, 1832, 666.— Aud. Cm. Biog. IV? 1838, 446 ; pi. 361.— Ib. Syn. 1839, 283.— 

 Ib. Birds Amer. 1, 1842, 89 ; pi. 295.— Newberry, Rep. P. R. R. Surv. VI, iv, 1857, 93. 



Canace ohscura, Bonap. Comptes Rendus, XLV, 1857, 428. 



Tetrao richardsonii, DonoLAS, Trans. Linn. Soc. XVl, 1829, 141. 



Sp. Ch Sexes dissimilar. Tailof twenty feathers. Above bluish black ; plumbeous or black beneath. Tail uniform black, and 



finely and obscurely mottled above. Tail broadly tipped with light slate. Beneath uniform plumbeous. A dusky half collar on the 

 throat. The chin and throat above white, varied with black. Tail about two-thirds the length of the wings, broad, rounded, com- 

 posed of twenty broad, even, and truncated featliers. Tarsi feathered to the toes, the feathers extending along the sides of the basal 

 half of the first joints of the toes. Pectinations on the sides of the toes very short. Length, 20.50 ; wing, 9.40 ; tail, 7.45. 



Jiab, — Black Hills of Nebraska to Cascade mountains of Oregon and Washington. 



