Birds of America
By John James Audubon, F. R. SS. L. & E.
GENUS I.--ORTHYX, Steph. AMERICAN PARTRIDGE.
Bill very short, robust, rather obtuse; upper mandible with the outline
decurved from the base, the ridge narrow at the base, on account of the breadth
of the nasal membrane, somewhat distinct in its whole length, with the sides
convex, the gap-line arched, the edges thin, without notch, the tip decurved,
thin-edged, obtuse; lower mandible with the angle short and rounded, the dorsal
line slightly convex, the sides rounded, the edges involute, the tip rounded.
Nostrils basal, linear, operculate, nearly concealed. Head of ordinary size,
ovato-oblong; neck rather short; body full. Feet of moderate length; tarsus
shorter than the middle toe, with two anterior series of large scales; first toe
small and elevated; third very long, second shorter than third, scutellate,
connected at the base by webs of a considerable extent. Claws rather stout,
arched, compressed, rather acute. Plumage dense, rather compact; wings short,
concave, rounded. Tail short, rounded, of twelve feathers. A bare space behind
the eyes. Tongue triangular, fleshy; oesophagus with an ovate oblique crop on
the fore part of the neck; stomach a very large and strong gizzard, broader than
long, placed obliquely, with concave grinding surfaces; intestine long and wide;