Bill very short, stout, broader than high at the base, with the upper
mandible convex, thin-edged, obtuse, the lower with the dorsal line
convex, the tip rounded. Head small, oblong; neck of moderate length,
or rather short; body very bulky. Feet rather of moderate length,
stout; tarsus bare, anteriorly scutellate; hind toe rather small,
third long, lateral nearly equal, all scutellate, anterior webbed at
the base. Claws moderate, arched, compressed, obtuse. Plumage full and
strong; feathers with the plumule much developed. Wings rather short,
convex, rounded. Tail generally short and rounded, of more than twelve
feathers. Tongue triangular, pointed; œsophagus with a very large
crop; stomach a very strong muscular gizzard, with the lateral muscles
highly developed, the epithelium dense, with two concave grinding
surfaces; intestine long, and of moderate width; cœca very large,
oblong, internally with reticulate ridges. Trachea without inferior
laryngeal muscles. Nest on the ground, rudely constructed. Eggs
numerous. Young covered with stiffish down.
GENUS I. ORTYX, 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 gape-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; œsophagus 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; cœca large.