Birds of America
By John James Audubon, F. R. SS. L. & E.
FAMILY XLII.--LARINAE. GULLS.
Bill of moderate length, straight, compressed, acute; upper mandible with
the dorsal line generally straight until toward the end, when it is decurved,
the ridge convex, the nasal groove rather long, the edges sharp, direct,
overlapping, the tip rather acute and declinate; lower mandible with the angle
long and very narrow, the dorsal line ascending and nearly straight, with an
angular prominence at its commencement. Nostrils sub-medial or basal, oblong.
Head of moderate size, ovate; neck of moderate length; body rather stout. Legs
short or of moderate length; tibia bare at its lower part; tarsus anteriorly
scutellate; toes four, the first very small, free, the third longest; anterior
toes connected by webs. Claws small, arched, compressed, rather acute. Plumage
full, soft, blended, somewhat compact on the back and wings, the latter long and
pointed; tail of twelve feathers, even, rounded, or emarginate. Tongue long,
slender, pointed; oesophagus very wide; stomach rather small, moderately
muscular, with a dense, longitudinally rugous epithelium; intestine of moderate
length and width; coeca small; cloaca globular. Trachea simple, with a single
pair of inferior laryngeal muscles. Nest on the ground, rudely constructed.
Eggs few, not exceeding four, spotted. Young covered with down.