_Turdus_, LINNÆUS, Syst. Nat., ed. 10, 1758, 168. (Type, _Turdus
viscivorus_ of Europe.)—BAIRD, Rev. Am. Birds.
GEN. CHAR. Bill conical, subulate, shorter than the head; the tip
gently decurved and notched (except in _Hesperocichla_); the rictus
with moderate bristles; the wings rather long and pointed, with small
first primary (less than one fourth the second); wings considerably
longer than the tail, which is firm, nearly even, with broad feathers.
Tarsi variable, seldom as long as the skull, the scutellæ fused into a
continuous plate, only in rare individual instances showing
indications of the lines of separation.
The genus _Turdus_ is very cosmopolitan, occurring nearly throughout
the globe, excepting in _Australia_, and embraces species of highest
perfection as singers. In the large number of species known there are
many variations in external form, but the transition from one to the
other is so gradual as to render it very difficult to separate them
into different genera. The sections of the group we adopt are the
following:—
_Sexes similar._
Hylocichla. Smallest species. Bill short, broad at base; much
depressed. Tarsi long and slender, longer than middle toe and claw, by
the additional length of the claw; outstretched legs reaching nearly
to tip of tail. Body slender. Color: above olivaceous or reddish,
beneath whitish; breast spotted; throat without spots.
Turdus. Bill stouter and higher. Tarsi stout and short, scarcely
longer than middle toe and claw. Body stout, generally whitish beneath
and spotted. (Second quill longer than fifth?)
Planesticus. Similar to preceding. (Second quill shorter than fifth?)
Beneath mostly uni-colored; unstreaked except the throat, which is
whitish with dark streaks.
_Sexes dissimilar._
Merula. Similar to _Turdus_. Male usually more or less black,
especially on the head; females brownish, often with streaked throats.
Bill distinctly notched.
Hesperocichla. Similar to _Turdus_. Male reddish beneath, with a black
collar. Bill without notch.