Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME VI.
GENUS V.--FULIGULA. SEA-DUCK.
Bill about the length of the head or shorter, higher than broad at the
base, depressed toward the end, the margins parallel, slightly dilated towards
the end, which is rounded, the frontal angles rather pointed; upper mandible
with the dorsal line generally declinate, but various at the base, being often
prominent, the ridge broad at the base, narrowed at the middle, enlarged and
convex at the end, the sides nearly erect at the base, gradually more declinate,
the edges soft and internally lamellate, the unguis oblong and decurved; lower
mandible flattened, being but slightly convex, with the angle very long and
rather narrow, the dorsal line very short and straight, the edges internally
lamellate, the unguis flat, obovato-elliptical. Nostrils sub-medial,
linear-oblong, rather large, near the ridge, in an oblong depression covered
with the soft membrane of the bill. Head rather large, compressed, convex
above; neck of moderate length, rather thick; body full, depressed. Feet very
short, strong, placed rather far behind; tarsus very short, compressed,
anteriorly with narrow scutella continuous with those of the middle toe, and
having another series commencing half-way down and continuous with those of the
outer toe; hind toe small, with an inner expanded margin; middle toe nearly
double the length of the tarsus, outer a little shorter, all scutellate. Claws
small, compressed, that of the first toe very small and curved. Plumage dense,
firm, blended. Wings shortish, narrow, pointed, first and second quills
longest; inner secondaries elongated and tapering. Tail very short, rounded or
cuneate, of fourteen or more feathers. OEsophagus rather wide, considerably
dilated at the lower part of the neck; stomach an extremely muscular, roundish
gizzard; intestine long and wide; coeca long. Trachea of the males with a
transverse, bony, unsymmetrical dilatation at the inferior larynx.