620 
U. S. P. E. R, EXP. AND SURVEYS-—ZOOLOGY—GENERAL REPORT. 
TETRAO, Linnaeus. 
Tctrao, Linnaf.us, Syst. Nat. 1744. Type T. urogallus, L. (Gray.) 
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 Tefrao, as defined by later 
writers, with T. urogallus for type. This species differs 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. 
Comparative measurements of species. 
Catal 
No. 
Species. 
Locality. 
Sex. 
Length. 
Stretch 
of wings. 
Wing. 
Tail. 
Tarsus. 
Middle 
toe. 
Its claw 
alone. 
Bill 
above. 
Along 
gape. 
Specimen 
measured. 
Tetrao obscurus .... 
3 
20.50 
9.40 
7.45 
1.65 
2.19 
0.46 
0 96 
1.19 
4398 
3 
18.60 
8 90 
6.8G 
1.66 
2.26 
0 56 
0.80 
1.05 
19.75 
30.00 
9.75 
5746 
3 
19.30 
9.00 
7.46 
1.62 
2.16 
0.52 
1 04 
1.20 
10013 
o 
18 50 
8.34 
5.90 
1.62 
2.06 
0.44 
1.00 
1.06 
do. 
V 
19.00 
27.00 
8.75 
Fresh.... 
7046 
Black Hills. 
o 
17.64 
8.40 
6.16 
1.61 
2.06 
0.46 
0.92 
1.14 
478 
V 
> 
16.20 
6.70 
5.44 
1.54 
1 86 
0.48 
0 85 
0.98 
Q 
12.70 
6.60 
4.56 
1.40 
1.76 
0.42 
0.74 
0.82 
10025 
3 
7.35 
5.62 
1.38 
1.83 
0.45 
0.84 
0.92 
10026 
Q 
6.90 
4.52f 
Feet an 
d head 
wanting 
* Very poor specimen. 
TETRAO OBSCURUS, Say. 
Dusky Grouse. 
Tetrao obscurus, Sat, Long’s Exped. R. Mts. II, 1823, 14. — Bon. Syn. 1828,127. —Ib. Mon. Tetrao, Am. Phil. Trans. 
Ill, 1830, 391.— Ib. Am. Orn. Ill, 1830 ; pi. xviii.—Sw. F. Bor. Am. II, 1831,344 ; pi. lix, lx.— 
Nuttall, Man. I, 1832, 666.— Aud. Orn. Biog. IV, 1838, 446 ; pi. 361.— Ib. Syn. 1839, 283.— 
Ib. Birds Amer. I, 1842, 89 ; pi. 295.— Newberry, Rep. P. R. R. Surv. VI, iv, 1857, 93. 
Canace obscura, Bonap. Compte3 Rendus, XLV, 1857, 428. 
Tetrao richardsonii, Douglas, Trans. Linn. Soc. XVI, 1829, 141. 
Sp. Ch.—S exes dissimilar. Tail of 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 feathers. 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. 
Hab —Black HiJIs of Nebraska to Cascade mountains of Oregon and Washington. 
