Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME I.
FAMILY VI. HIRUNDINAE. SWALLOWS.
Bill very short, much depressed and very broad at the base, compressed
toward the tip; upper mandible with the dorsal line convex, the edges
overlapping, with a small notch close to the slightly decurved tip. Head broad,
depressed; neck very short, body moderate. Feet very short, tarsus very short,
anteriorly scutellate; toes of moderate size; first large, all scutellate in
their whole length; claws rather strong, compressed, well curved, acute.
Plumage soft, blended, glossy. No bristles at the base of the bill. Wings
extremely long, narrow, pointed, somewhat falciform; secondaries very short.
Tail generally emarginate, of twelve feathers. Mouth extremely wide; oesophagus
rather wide, without crop; stomach elliptical or roundish, muscular, with a
dense rugous epithelium; coeca very small. Four pairs of inferior laryngeal
muscles. Nest in holes in banks, buildings, or trees, or attached to the
surface of these objects. Eggs from four to six, white, plain, or spotted.