Birds of America
By John James Audubon, F. R. SS. L. & E.
GENUS I.--PHALACROCORAX, Briss. CORMORANT.
Bill about the length of the head, rather slender, nearly straight,
compressed toward the end; upper mandible with the dorsal line concave, until on
the unguis, where it is decurved, the ridge convex, flattened toward the end,
separated from the sides by a narrow groove, the sides convex, the edge sharp
and nearly straight as far as the unguis, which is decurved, convex above,
acute, its tip ascending far beyond that of the lower; lower mandible with the
angle long and very narrow towards the end, filled up by an extensile membrane,
which extends to the level of the angle of the mouth; the outline of the crura
very slightly convex, that of the terminal part descending and very slightly
convex, the sides convex, the edges sharp and inflected, the tip compressed,
with its marginal outline decurved. Nostrils obliterated (in youth open). Head
rather small, oblong; neck long and rather thick; body full, elongated,
depressed. Feet short, stout, placed far behind; tibia feathered in its whole
length; tarsus very short, strong, milch depressed, covered all round with
angular scales; a series on part of the inner side anteriorly, and another on
the lower part of the outer, scutelliform. Toes all placed in the same plane,
connected by webs, and covered above by very numerous oblique scutella; first
the smallest, fourth the longest. Claws rather small, strong, compressed,
acute, convex above, arched, that of the third toe pectinated on its inner edge.
Plumage soft, generally blended, compact on the back and wings; the small gular
sac, and the space before and beneath the eye, with the eyelids, bare. Wings of
moderate size, broad; primaries curved, pointed, the second longest. Tail of
moderate length, very narrow, much rounded, of twelve or more narrow
strong-shafted feathers. Gular sac small; tongue extremely small; oesophagus
very wide; proventricular glands disposed in two large roundish masses; stomach
small, slightly muscular, inner coat smooth and soft; a globular or triangular
pyloric lobe; duodenum at first curving upwards; intestine very long, and of
moderate width; coeca small; rectum narrow; cloaca globular. Trachea
considerably flattened; bronchi of moderate width.