CHAR. Primaries nine. Bill very short, abruptly conical, and robust.
Commissure strongly angulated at base of bill. Tarsi scutellate
anteriorly, but the sides with two undivided plates meeting behind
along the median line, as a sharp posterior ridge. Eyes hazel or
brown, except in _Pipilo_, where they are reddish or yellowish. Nest
and eggs very variable as to character and situation.
I still labor under the inability expressed in Birds of North America
(p. 406), in 1858, to satisfactorily define and limit the subfamilies
and genera of the _Fringillidæ_ of North America, and can only hope
that by the aid of the figures of the present work no material
difficulty will be experienced in determining the species. The
distinctions from the allied families are also difficult to draw with
precision. This is especially the case with the _Tanagridæ_, where we
have much the same external anatomy, including the bill, nearly all
the varying peculiarities of this member in the one being repeated in
the other.—S. F. B.
All the United States species may be provisionally divided into four
subfamilies (the European House-Sparrow forming a fifth), briefly
characterizable as follows:—
Coccothraustinæ. Bill variable, from enormously large to quite
small; the base of the upper mandible almost always provided with a
close-pressed fringe of bristly feathers (more or less conspicuous)
concealing the nostrils. Wings very long and pointed, usually one half
to one third longer than the forked or emarginate tail. Tarsi short.
Pyrgitinæ. Bill robust, swollen, arched above without distinct
ridge. Lower mandible at base narrower than upper. Nostrils covered;
side of maxilla with stiff appressed bristles. Tarsi short, not longer
than middle toe. Tail shorter than the somewhat pointed wings. Back
streaked; under parts not streaked.
Spizellinæ. Embracing all the plain-colored sparrow-like species
marked with longitudinal stripes. Bill conical, always rather small;
both mandibles about equal. Tarsi lengthened. Wings and tail variable.
Lateral claws never reaching beyond the base of the middle claw.
Passerellinæ. Sparrow-like species, with triangular spots beneath.
Legs, toes, and claws very stout; the lateral claws reaching nearly to
the end of the middle ones.
Spizinæ. Brightly colored species, usually without streaks. Bill
usually very large and much curved; lower mandible wider than the
upper. Wings moderately long. Tail variable.