A. Oscines. Musical apparatus highly developed. Back of tarsus
undivided, or formed of a few scutella distinct from those
lapping over the front. First primary wanting, spurious, or at
most not over two thirds the length of the longest.
_a._ Each side of tarsus covered with a plate undivided in
most or all of its length, and meeting its fellow in a
sharp ridge behind.
_b._ Primaries only nine.
_c._ Bill triangular, depressed, about as wide at base as
long; the gape twice as long as the culmen, reaching to
about opposite the eyes; tomia straight or gently curved.
No obvious rictal bristles. Tarsi not longer than the
lateral toe and claw. Wings long and pointed, the first
primary equal to or longer than the second. Central
tail-feathers not half as long as the wing … _Hirundinidæ_.
_cc._ Bill variously conico-elongate or slender, or, if
depressed, with long rictal bristles; gape not nearly twice
as long as culmen; tomia straight or gently curved.
Nostrils not obviously nearer culmen than tomia. Tarsus
longer than lateral toe and claw.
Bill very slender, acute; culmen rather concave at base.
Longest secondary acuminate, nearly or quite equal to the
primaries in the closed wing. Hind claw little curved,
about twice as long as the middle claw. Hind toe and claw
longer than middle toe and claw … _Motacillidæ_.
Bill variously conico-elongate and acute; culmen not
concave at base. Longest secondary not acuminate, falling
far short of primaries in the closed wing. Hind claw well
curved, not nearly twice as long as middle claw; hind toe
and claw not longer than middle toe and claw. Gape ample;
tongue slightly bifid or brushy, if at all … _Sylvicolidæ_.
Bill lengthened, very acute, even decurved. Wings and
feet as in the last. Gape constricted; tongue generally
deeply bifid or brushy … _Cærebidæ_.
_ccc._ Bill more or less truly conic, usually short, thick;
commissure usually more or less evidently abruptly
angulated near the base, or with lobe or tooth further
forward. Nostrils obviously nearer culmen than tomia.
Tarsus longer than lateral toe and claw.[13]
Bill stout, tumid, convex in nearly all its outlines;
tomia not angulated, but with one or more lobes or nicks
in advance of the base. Nostrils placed very high. Other
characters much as in _Sylvicolidæ_. Colors chiefly red
and yellow. One genus of … _Tanagridæ_.
Bill truly conic, much shorter than head, usually with
the angulation evident; no lobe along middle of tomia,
but usually a notch at end. Nostrils placed very high.
Rictal bristles usually obvious … _Fringillidæ_.
Bill conic, but lengthened, little if any shorter than
head; the angulation of the tomia evident; no notch at
end. Nostrils high. No rictal bristles … _Icteridæ_.
_bb._ Primaries ten.
Otherwise with characters much as in _Icteridæ_ … _Sturnidæ_.
_d._ Nostrils concealed with antrorse bristly feathers
(except in _Psilorhinus_ and _Gymnokitta_).[14]
Base of bill sheathed with antrorse bristly feathers,
having lateral branches to their very ends; its tip
mostly notched. Basal joint of middle toe united only
half-way to the lateral. Sides of tarsus occupied by a
lateral groove, mostly filled in with small plates. First
primary more than half as long as second. Large,—over
seven inches … _Corvidæ_.
Base of bill with two tufts of bristly feathers, ending
in simple filaments without lateral branches, its tip
mostly unnotched. Basal joint of middle toe united nearly
all its length with the lateral. Sides of tarsus
ungrooved. First primary less than half as long as
second. Small,—under seven inches … _Paridæ_.[15]
_dd._ Nostrils exposed.
_e._ Tail scansorial, with rigid acute feathers. Whole
bill slender, compressed, acute, decurved, unnotched,
unbristled. Outer toe much longer than inner … _Certhiidæ_.
_ee._ Tail not scansorial, graduated. First primary not
less (generally more) than half as long as the second,
and inner toe united to the middle by at least one half
(usually more) of the length of its basal joint.
Tarsus with few obscure scutella. Rictal bristles
present. Bill stout, but not toothed nor hooked. Wing
excessively rounded (fifth, sixth, and seventh
primaries longest), much shorter than the long
graduated tail. Size small. Plumage brown, unbanded …
_Chamæadæ_.
Tarsus distinctly scutellate. Nostrils wholly
exposed, scaled. No rictal bristles, but loral
feathers with bristly points. Bill slender, not
notched nor hooked. Wings and tail moderately
rounded; neither very much shorter than the other.
Size small. Color brown, etc., the wings and tail
barred or undulated … _Troglodytidæ_.
Tarsus distinctly scutellate. Nostrils overhung (not
concealed) with bristly feathers. Rictal bristles
present, strong. Bill powerful, compressed, strongly
notched, toothed, and hooked. Wings and tail
moderate. Large. Colors black, white, and gray …
_Laniidæ_.
_eee._ Tail not scansorial. First primary less than
half as long as the second,[16] or about half as long,
in which case the inner toe is cleft nearly to its base
(_f_ and _ff_).
_f._ Basal joint of middle toe united some distance
with the inner, and for half or more of its length
with the outer toe.
Basal joint of middle toe shorter than that of
inner toe, and wholly adherent to both inner and
outer toes. Tarsus longer than middle toe and claw.
Gonys more than half the length of the lower jaw.
Bill stout, high, compressed; notched and abruptly
hooked at tip … _Vireonidæ_.
Basal joint of middle toe not shorter than that of
inner toe; united to the outer for about two
thirds, to the inner for about one half, its
length. Tarsus not longer than the middle toe and
claw. Gonys less than half the length of the under
jaw. Bill triangular, much depressed at base,
moderately notched, and hooked at tip[17] … _Ampelidæ_.
Basal joint of middle toe shorter than that of the
inner toe, united to the outer for about two
thirds, to the inner for about one half, its
length. Tarsus longer than middle toe and claw.
Gonys more than half the length of the under jaw.
Bill very weak and slender, little decurved or
notched at tip. Very small,—under six inches long.
(Tarsi booted in _Regulus_, distinctly scutellate
in _Polioptila_.) … _Sylviidæ_.
_ff._ Basal joint of middle toe quite free from the
inner, and not united with the outer more than
half-way.
Nostrils linear, low. No bristles or bristly points
whatever about the mouth. Wings short, rounded,
concavo-convex. Tail very short, nearly concealed
by its coverts. Tarsi booted … _Cinclidæ_.
Nostrils oval. Bristles or bristly points about the
mouth. Wings very long and pointed, reaching, when
folded, beyond the middle of the short, square, or
emarginate tail, and one and a half times or more
the length of the latter; tip formed by second,
third, and fourth quills; outer secondary reaching
only about two thirds way to end of longest
primary; spurious quill very short. Tarsi booted …
_Saxicolidæ_.
Nostrils oval. Bristles or bristly points about the
mouth. Wings moderate, not reaching, when folded,
beyond the middle of the tail, and not over one and
a third times as long as the latter; tip formed by
third to sixth quill; outer secondary reaching in
closed wing three fourths or more the length of the
longest primary. Spurious quill longer, sometimes
one half the second. Tarsi scutellate in _Miminæ_,
booted in _Turdinæ_ … _Turdidæ_.
_aa._ Outside of tarsus covered with two series of
scutella,—one lapping entirely around in front, the other
entirely around behind, and meeting at a groove on the inside;
hind edge blunt. First primary spurious or apparently wanting.
Hind claw much lengthened, scarcely curved. Nostrils with
antrorse bristly feathers. Bill conico-elongate … _Alaudidæ_.
B. Clamatores. Outside of tarsus covered with a series of plates
variously arranged, lapping entirely around in front and behind,
to meet at a groove on the inner side.
First primary lengthened, often longest, at least over two thirds
as long as the longest. Bill broad at the base, much depressed,
tapering to a fine point, which is abruptly decurved; culmen
rounded or flattened; gonys flattened; commissure straight, or
nearly so, to the tip. Nostrils small, circular, basal; overhung,
but not concealed by bristles. Mouth capacious, with broad and
deeply fissured rictus, beset with numerous long strong bristles.
Feet small, weak. Tail of twelve feathers … _Tyrannidæ_.