We have thus completed the account of the Oscine Singing-Birds with slender bills not hooked at the end, and which have ten distinct primaries; the first or outer one, however, either quite small or else considerably shorter than the second. We now come to a series with only nine primaries, the first being entirely wanting, and the second, now the outermost, nearly or quite as long as the third. In the preliminary tables of general arrangement will be found the comparative characters of the different families of Oscines, but the diagnosis of the series referred to is presented here, as follows:—
Common Characters. Primaries nine; the first quill nearly as long as the second or third. Tarsi distinctly scutellate the whole length anteriorly. Bill conical, but slender or depressed, usually, except in Cærebidæ, half the length of the head; more or less bristled, or notched. Nostrils oval or rounded. Lateral toes nearly or quite equal, and shorter than the middle; the basal joint of the middle free nearly to its base externally, united for about half internally.
Motacillidæ. Bill slender. Culmen slightly concave at base. Legs long; claws but little curved. Hind toe considerably longer than the middle one; its claw much longer (twice) than the middle claw; all the claws but slightly curved. Innermost secondaries (so-called tertials) elongated, much longer than the outer secondaries; and the fifth primary emarginated at end. Nest on ground.
Sylvicolidæ. Bill rather slender, conical, or depressed. Culmen straight or convex. Hind toe shorter than the middle; the claws all much curved. Hind claw not conspicuously longer than the middle one. When the hind toe is lengthened, it is usually in the digit, not the claw. Tertials generally not longer than the secondaries, and not emarginated. Gape wide; tongue slightly split at end. Nest variously placed.
Cærebidæ. Similar to Sylvicolidæ. Bill generally longer; equal to head or more. Gape of mouth narrow; tongue generally much fringed at the end. Nest on trees.
The Tanagridæ, the Fringillidæ, and even the Icteridæ, come very near these families, as will be explained farther on, all agreeing in having the nine primaries, and in many other characters.
Family MOTACILLIDÆ.—The Wagtails.
Char. Bill slender, conical, nearly as high as wide at the base, with slight notch at the tip; the culmen slightly concave above the anterior extremity of the nostrils; short bristles at gape, which, however, do not extend forward to nostrils. Loral feathers soft and dense, but with bristly points; nasal groove filled with naked membrane, with the elongated nostrils in lower edge; the frontal feathers coming up to the aperture, but not directed forward nor overhanging it. Wings lengthened and sharp-pointed; the primaries nine (without spurious first), of which the first three to five, considerably longer than the succeeding, form the tip; the exterior secondaries generally much emarginated at the ends; the inner secondaries (so-called tertials) nearly equal to the longest primaries. The tail rather narrow, emarginate. Tarsi lengthened, scutellate anteriorly only, the hind claw usually very long, acute, and but slightly curved (except in Motacilla). Inner toe cleft almost to the very base, outer adherent for basal joint only.
The combination of naked nostrils, notched bill, and nine primaries, with the tarsi scutellate anteriorly only, will at once distinguish the Anthinæ of this family from the Alaudidæ, which they so closely resemble in coloration, habits, and lengthened hind claw. The lengthened, slightly curved hind claw, much pointed wings, emarginated secondaries,—the inner ones nearly as long as the primaries,—distinguish the family from the Sylvicolidæ, with which also it has near relationships.