12 CANVASS-BACK DUCK.
head small and rather compact, of the rest of the head and neek small,
blended, and glossy. Wings shortish,narrow,pointed; primary quills
strong, tapering, the first longest, the second almost as long, the rest
rapidly diminishing; secondary quills broad and rounded, the inner
elongated and tapering. Tail very short, much rounded, or wedgeshaped,
of fourteen feathers.
Bill black, with a tinge of green, Iris bright carmine. Upper
part of the head, and a space along the base of the bill dusky ; a small
transverse band of white on what is called the chin; the rest of. the
head, and the neck all round, for more than half its length, of a rich
brownish-red. A broad belt of brownish-black occupies the lower
part of the neck, and the fore part of the body, of which the posterior
part is of the same colour, more extended on the back than under the
tail. Back and scapulars white or greyish-white, very minutely traversed
by undulating black lines ; wing-coverts, similar but darker.
s
>2:
r,Alular feathers greyish-brown. Primary quills brownish-hlaek., tinged
with grey towards the base; the shaft brown. r,.|t»daries.asli-gr8y.,
whitish, and undulated with .dark grey towards the end ; - live of thorn
also having a narrow stripe of blaekalong their outers margin. Tail
brownish-grey, towards the end ash-grey, i The lower parts white;,, the
sides and abdomen marked with- fine .undulating grey lines,,, of which,
there: are faint traces- on most of the other.-,feathers. Tie,feet are
greyish-blue tinged with yellow, ,
<j,¡Length to end of tail 2.2.,,inches't^n<t£c?f wings 20, to end of
claws 25 ;,extentof wings 33 ; wing, from flexure, ; tail 2|£ ; bill
along the back, measured from the.-tipiofvthg^lsantal p roc^; to the
end of the unguis, 3-; lower mandible, along the,edge 2,?a,; tarsus I f ;
first to.e.'.jV its claw ^ ¡middl e toe..jJ,-.it£ claw .; outer too,
scarcely shorter; inner, r l shorter. .Weight 3J lb.
Adult Female. Plate CCCX- . Fig.
The Female has the bill coloured as in the male; the iris reddishbrown
; the feet lcad-grev ; the upper,, parts greyish-brown ; the
top of the head darker,, its anterior part light reddish.;- the chin
whitish; the neck greyisli-brown, as arc tlie,si(i.e.s and abdomen; the!
breast white ; wing-coverts brownish-grey ; primary quills greyishbrown,
dusky at the end; -secondary quills ash-grey, five of the inner
with an external black margin, the innermost greyishhrown,like the
CANVASS-BACK DUCK. 13
back, and with some of the scapulars faintly undulated with darker.
Tail, greyish-brown, paler , at the end ; axillars and smaller under
wing-coverts white, as in the male.
Length to end of tail, 20£ inehes, to end of wings 18i, to end of claws,
23J-;''extout of wings, 30j : wing from flexure, Weigh 2 | lb.
This species'- is very closely allied to the Pochard, or Bed-headed
Duck, FulUjula Ferina, but is much larger, and differs in having the
bill proportionally higher at the base, and less, dilated towards the end.
The colours are also generally similar, but present differences. The
upper parts of the Canvass-back are much whiter than those: of the
Pochard; the head of the former is dusky above, of the latter uniform
with the neek ; and the white spot on the chin is wanting in the
Pochard.
The Digestive and Re'spiratory Organs of a male shot near Baltimore
present the following characters.
The upper mandible is broadly and deeply concave. The tongue,
which is thick and fleshy, as in other -ducks, is 2T% inches long, its-sides
parallel, slightly sloping, and furnished with- two Series of bristly filaments;
its b'ase with numerous -straight conical papilla; directed backwards,
its upper surface marked with a broad median groove, the lower
flat, its extremity formed by a thin semi-circular appendage, a quarter
of an inch in length. Thè oesophagus passes along the right side of the
neck, six inches, has a diameter of then dilates to so as to
form a slight crop; again contracts as it enters the thorax, and in terminating
forms the proventriculus, which is If inches in length,
with oblong glandules,» generally a twelfth of an inch in length. The
stomach is a very large- and- powerful gizzard, of a broadly elliptical
form, with extremely thick lateral muscles, the left being -JJ in thickness,
the right J J, the tendons large and strong: * The transverse diameter
of the' gizzard is 2£§ inches, the longitudinal, from the cardiac orifice
to the bulge of the' inferior muscle, 2i5 . Its cuticular lining is of very
dense texture, and rugous ; the grinding plates opposite the lateral
muscles about half a twelfth thick, and Slightly rugous. The intestine,
which is 5 feet 9 inches in length, first forms in the usual manner the
duodenal fold, at the distance of 5 inches from the pylorus, encloses the
pancreas, receives the biliary ducts, and passing under, the right lobe