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 transvei'sely in close- 

 set, zigzag lines, on a pale ground, more or less shaded off 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, 

 coiTesponds 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- 

 rass-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, nan'ow, grass-like blades of four or or five feet 



