Scutellæ very distinct; gonys straight, or even declining at tip … Mimus.
Scutellæ more or less obsolete; gonys convex, ascending at tip … Galeoscoptes.
Bill not notched at tip, lengthened; sometimes much decurved … Harporhynchus.
Note.—In the Review of American Birds, I., May, 1866, 409, I have advanced the suggestion that the N. American genus Myiadestes, usually placed under the Ampelidæ, really belongs under Turdidæ in a group Myiadestinæ. The relationships are certainly very close, as is shown by the characters given below.
Common Characters.—Tarsi without regular transverse scutellæ, except at lower end. Wings acute, pointed, as long as or longer than tail, which is but slightly graduated. First primary rarely half second, which exceeds the secondaries. Base of quills buffy yellow, as are inner edges. Tail spotted or varied at the end. Young birds with many light spots. Very melodious singers.
Myiadestinæ. Bill short, much depressed; mouth deeply cleft; width at base about equal to the distance from nostril to tip, or greater; commissure more than twice distance from nostrils to tip of bill, and nearly two and a half times length of gonys. Legs weak; tarsi rather longer than middle toe and claw. Tail feathers tapering slightly from base to near tip, giving a slightly cuneate appearance to the tail.
Turdinæ. Bill stouter, more lengthened; narrow at base and more compressed; width at base less than distance from nostril to tip; commissure not more than twice distance from nostrils to tip of bill, and about twice length of gonys. Tarsi stouter, longer than middle toe and claw. Tail feathers widening slightly from base to near tip, giving a parallel-sided or slightly fan-shaped appearance to the tail.
The Miminæ differ, as already mentioned, in the scutellate tarsi: more rounded wings, etc.—S. F. B.
Subfamily TURDINÆ.
There are several American genera of Turdinæ not found north of Mexico as yet, although it is not impossible that one of these (Catharus) may hereafter be detected within the limits of the United States. The species of Catharus resemble the North American wood-thrushes (Hylocichla); but the spurious or first primary quill is longer (from one half to one third the second quill), the wings are rounded, not pointed, the tarsus is longer than the head, and the outstretched toes extend beyond the tail. The species to be looked for are C. melpomene and occidentalis.[22]