Birds of America
By John James Audubon, F. R. SS. L. & E.
GENUS XVI.--COCCOBORUS, Swains. SONG-GROSBEAK.
Bill rather short, extremely robust, almost as broad as the head, and
somewhat compressed, tapering to a point; upper mandible considerably smaller
than the lower, with the dorsal line convex, the ridge indistinct, the nasal
sinus very wide, the sides convex, the edges ascending for a third of their
length, then direct, with a slight festoon, and inflected, the notches faint,
the tip a little, deflected, and narrow; lower mandible with the angle short and
semicircular, the dorsal line straight, the sides at the base inflected, toward
the end convex, the edges involute, the tip acute. Nostrils basal, round.
Plumage somewhat compact, blended; distinct bristles at the base of the upper
mandible. Wings of moderate length, pointed, the outer three quills nearly
equal, the second longest. Tail of moderate length, slightly emarginate.
Tarsus short, compressed, with seven scutella; toes moderate, hind toe stout,
broad beneath, outer toe slightly longer than inner, and adherent at the base.
Claws moderate, arched, compressed, acute. Upper mandible concave beneath, with
three longitudinal ridges; tongue as high as broad, convex above, tapering to a
point; oesophagus rather wide, dilated about the middle; stomach rather small,
roundish, compressed, with its muscles distinct and of moderate thickness, the
epithelium longitudinally rugous; intestine short, and of moderate width; coeca