76 
FRANK FORESTER’S FIELD SPORTS. 
measures two feet in length by three feet in extent, and when in 
the best order, weighs three pounds and over. The Pochard, 
according to Latham and Bewick, measures nineteen inches 
in length, and thirty in extent, and weighs one pound twelve 
or thirteen ounces. The latter writer says, of the Pochard: 
* The plumage above and below is wholly covered with prettily- 
freckled, slender, dusky, threads, disposed transversely in close- 
set, zigzag lines, on a pale ground, more or less shaded oif with 
ash, a description much more applicable to the bird figured be¬ 
side it, the Red-head, and which very probably is the species 
meant. In the figure of the Pochard, given by Mr. Bewick, 
who is generally correct, the bill agrees very well with that of 
our Red-head, but scarcely half the size and thickness of that 
of the Canvass-back, and the figure in the planches enluminees, 
corresponds in that respect with Bewick’s. In short, both of 
these writers are egregiously erroneous in their figures and de¬ 
scriptions, or the present Duck was unknown to them. Consid¬ 
ering the latter supposition the more probable of the two, I 
have designated this as a new species, and shall proceed to give 
some particulars of its history. 
“ The Canvass-back Duck arrives in the United States from 
the North about the middle of October; a few descend to the 
Hudson and Delaware, but the great body of these birds resort 
to the numerous rivers belonging to, and in the neighborhood of, 
Chesapeake Bay, particularly the Susquehanna, the Patapsco, 
Potomac and James Rivers, which appear to be the general 
winter rendezvous. Beyond, to the South, I can find no certain 
accounts of them. At the Susquehanna they are called Can- 
vass-backs, on the Potomac, White-backs, and on James River, 
Shell-drakes. They are seldom found at a great distance up 
any of these rivers, or even in the salt water bay, but in that 
particular part of tide-water where a certain grass-like plant 
grows, on the roots of which they feed. This plant, which is 
said to be a species of valisneria , grows on fresh water shoals 
of from seven to nine feet, (but never where these are occasion¬ 
ally dry,) in long, narrow, grass-like blades of four or or five feet 
