368 DUSKY GROUSE. 
At first sight, the Zenaida dove might perhaps be mistaken 
for the common turtle-dove (Columba Oarolinensis and margi- 
nata of authors), having the same general colour and several 
common markings ; but, to mention no other differential cha- 
racter, the short even tail, composed of but twelve feathers, all 
rounded, the outer bluish grey at tip, will at once distinguish 
it from the latter, which belongs to a different group, having 
the tail long, cuneiform, and (what is found in no other Ame- 
rican species, not even its close relation the passenger pigeon) 
composed of fourteen tapering and acute feathers, the two 
middle remarkably so, and the lateral pure white at tip. If 
any other distinction should be required, the white tips of the 
secondaries of our new species will afford a good one, as well 
as the outer tail-feather, the exterior web of which is blue 
erey, crossed, as well as the others, by the black band ; whilst 
in the C. Carolinensis it is entirely pure white, the black band 
being confined to the inner web. 
DUSKY GROUSE. (Tetrao obscurus.) 
PLATE XVIII.—-FEMALE. 
Tetrao obscurus, Say, in Long’s Exped. to Rocky Mount. ii. p. 14.—WNob. Cat. 
Birds U.S. sp. 209, in Contr. Macl. Lyc. Phila. i. p. 23.—Id. Syn. Birds 
U.S. sp. 207, in Ann. Lyc. Nat. Hist. N. Y. pp. 127, 442.—Philadelphia 
Museum, female.—Collection of Mr Sabine, in London, male and female. 
TETRAO OBSCURUS.—Say.* 
Tetrao obscurus, Worth. Zool. ii. p. 334, plate 59, male ; 60, female. 
Liynf, in his genus Vetrao, brought together so great a 
number of species bearing no more than a distant resemblance 
* The authors of the “ Northern Zoology” have given a beautiful figure 
of this bird, and have quoted the 7’. Richardsonii of Douglas as identical 
with it. This I am unable to decide, but should certainly give some 
weight to the comparisons of Dr Richardson, who thinks that those de- 
posited in the Edinburgh Museum are only younger specimens. 
The characters given by Mr Douglas are :— 
