SPECIES 18. AN^S VJiLISINERM. 
CANVAS-BACK DUCK. 
[Plate LXX.— Fig. 5.] 
Peale’s Museum, JVo. 2816. 
This celebrated American species, as far as can be judged 
from the best figures and descriptions of foreign birds, is alto- 
gether unknown in Europe. It approaches nearest to the Pochard 
of England, Jinas ferina, but differs from that bird in being 
superior in size and weight, in the greater magnitude of its bill, 
and the general whiteness of its plumage. A short comparison 
of the two will elucidate this point. The Canvas-back measures 
two feet in length, by three feet in extent, and when in the best 
order weighs three pounds and upwards. The Pochard, accord- 
ing 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 slen- 
der dusky threads disposed transversely in close set zig-zag lines, 
on a pale ground, more or less shaded off with ash;” a descrip- 
tion much more applicable to the bird figured beside 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 is scarcely half the size and thickness of that of the Canvas- 
back; and the figure in the Planches Enluminees corresponds 
in that respect with Bewick’s. In short, either these writers are 
egregiously erroneous in their figures and descriptions, or the 
present Duck was altogether unknown to them. Considering the 
latter supposition the more probable of the two, I have desig- 
nated this as a new species, and shall proceed to detail some 
particulars of its history. 
