CANVAS-BACK DUCK. 33 
coverts, grey, with numerous specks of blackish ; primaries 
and secondaries, pale slate, two or three of the latter of which 
nearest the body are finely edged with deep velvety black, the 
former dusky at the tips; tail, very short, pointed, consisting of 
fourteen feathers of a hoary brown; vent and tail-coverts, 
black ; lining of the wing, white; legs and feet, very pale ash, 
the latter three inches in width, a circumstance which partly 
accounts for its great powers of swimming. 
The female is somewhat less than the male, and weighs two 
pounds and three-quarters ; the crown is blackish brown ; 
cheeks and throat of a pale drab ; neck, dull brown ; breast, 
as far as the black extends on the male, dull brown, skirted 
in places with pale drab; back, dusky white, crossed with 
fine waving lines; belly, of the same dull white, pencilled 
like the back; wings, feet, and bill, as in the male; tail- 
coverts, dusky ; vent, white, waved with brown. 
The windpipe of the male has a large flattish concave 
labyrinth, the ridge of which is covered with a thin transparent 
membrane; where the trachea enters this, it is very narrow, 
but immediately above swells to three times that diameter. 
The intestines are wide, and measure five feet in length. 
Mr Ord, in his reprint, has added the following interesting 
observations :—‘*‘ It is a circumstance calculated to excite our 
surprise, that the canvas-back, one of the commonest. species 
of our country, a duck which frequents the waters of the 
Chesapeake in flocks of countless thousands, should yet have 
been either overlooked by the naturalists of Europe, or con- 
founded with the pochard, a species whose characters are so 
obviously different. But that this is the fact the editor feels 
well assured, since he has carefully examined every author of 
repute to which he has had access, and has not been enabled 
to find any description which will correspond to the subject 
before us. The species, then, we hope, will stand as Wilson's 
own; anditis no small addition to the fame of the ‘‘ American 
Ornithology ” that it contains the first scientific account of the 
finest duck that any country can boast of. 
VOL. IIL. C 
