Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME VII.
GENUS I.--LESTRIS, Illiger. JAGER.
Bill shorter than the head, strong, slightly compressed, straight, with the
tip curved; upper mandible with the dorsal line nearly straight, toward the tip
decurved, the ridge broad and convex, formed by two plates, which overlap the
nostrils, the sides narrow and convex, the edges sharp and inflected, the tip or
unguis decurved, compressed, acute; nasal groove long, narrow; the nostrils in
its fore part medial, lateral, longitudinal, broad before, extremely narrow
behind, open and pervious; lower mandible with the angle long and narrow, a
slight prominence at its extremity, beyond which the dorsal line is slightly
concave, the sides erect, and slightly convex, the edges sharp and inflected,
the tip obliquely truncate. Head rather large; neck of moderate length; body
rather full. Feet of moderate length, rather stout; tibia bare at its lower
part, and rough all round, with small convex scales; tarsus compressed behind
and scabrous, anteriorly scutellate; hind toe extremely small and elevated; fore
toes of moderate size, connected by convex webs, the third toe longest, the
fourth little shorter. Claws strong, much curved, very acute, compressed.
Plumage full, soft, blended, on the back rather compact. Wings very long,
rather broad, pointed, the first quill longest. Tail of moderate length, or
elongated, of twelve feathers, of which the middle are longest. Tongue broadly
channelled above, contracted and induplicate toward the end, with the point
slit; oesophagus very wide; stomach small, moderately muscular, with the
epithelium thin, dense, and longitudinally rugous; intestine rather short and
wide; coeca rather long; cloaca oblong.