Birds of America
By John James Audubon, F. R. SS. L. & E.
FAMILY XXIII.--SITTINAE. NUTHATCHES.
Bill of moderate length or rather long, straight, rather slender,
conico-subulate, somewhat compressed, with the tips acute, or cuneate. Head
ovate; neck short; body full. Tarsi rather short, or of moderate length,
slender, compressed, with seven or eight scutella; toes long, very slender; hind
toe extremely long; anterior little spreading; claws long, little arched,
slender, much compressed, acute. Plumage soft and full. Wings of moderate
length, broad, rounded. Tail short, broad, of twelve feathers. Roof of upper
mandible very narrow, slightly concave, with three ridges; tongue very slender,
with the tip abrupt and bristly; oesophagus without dilatation; stomach
roundish, moderately muscular; intestine short and wide; coeca very small.
Trachea simple; with a single pair of large inferior laryngeal muscles. Allied
to the Titmice on the one hand, and the Woodpeckers on the other.