CHAR. Primaries nine. Bill usually conical, sometimes depressed or
attenuated, usually more or less triangular at base, and with the
cutting edges not much inflected; sometimes toothed or notched. Legs
short; claws curved; colors usually brilliant.
We confess our entire inability to present a diagnosis that shall
define and separate satisfactorily by external characters the closely
allied families of _Cærebidæ_, _Sylvicolidæ_, _Tanagridæ_, and
_Fringillidæ_, agreeing as they do in the main in every respect. The
only attempt at distinction is based upon the shape of the bill, and
this in what are generally called _Tanagridæ_ presents every variety
of shape, from the attenuation seen in _Dendroica_ to the stoutest
form of the _Fringillidæ_. The _Cærebidæ_ have peculiarities of the
tongue, not appreciable, however, in the skin. In view, therefore, of
the difficulty in question, we shall copy the conventional names and
unsatisfactory definitions of other authors, in our inability to
present a satisfactory arrangement of our own.
Carus and Gerstæcker in Handbuch der Zoologie, I, 277, adopt a
classification of the _Oscines_ based on the palatine bones in which
_Fringillidæ_ and _Tanagridæ_ are distinguished from the _Sylvicolidæ_
as follows:—
Suborder OSCINES, SUNDEVALL. Of the ten primaries, the first is short,
rudimentary, or wanting; the number of secondaries is rarely more than
nine. Tarsus entirely booted, or else with an undivided plate on the
sides. Lower trachea completely formed by the help of the trachea and
bronchiæ; generally with four pairs of muscles, distributed before and
behind.
GROUP I. SPIZOGNATHÆ. Outer lamella of the palatine bone developed in
a vertical plane, with the hinder border more or less emarginated; the
anterior palatine process broad, and united by a truncated border to
the high and broad upper mandible.
FAMILY 1. _Ploceidæ._ Ten primaries.
FAMILY 2. _Fringillidæ._ Bill encircled by a more or less distinct
swelling at base. Frontal feathers not forming lateral angles. Edges
of the jaws drawn in as far as the corner of the mouth; nine
primaries; the first three usually longest. Legs with undivided plates
behind.
FAMILY 3. _Tanagridæ._ Bill more or less triangular at the base.
Culmen always more or less curved. Frequently a tooth or notch in the
upper bill, sometimes fine serrations. Wings moderate; somewhat
pointed; primaries nine. Tarsus and toes short and stout. Hind toe
stout and long. Claws curved.
GROUP II. CORÆOGNATHÆ. Palatine bone broad and rather flat behind, the
external angles prolonged, not extended into a vertical plate. Base of
bill generally narrower. Primaries nine or ten. This section embraces,
of North American forms:—
Mniotiltidæ,
Motacillidæ,
Alaudidæ,
Sylviidæ,
Turdidæ,
Cærebidæ,
Hirundinidæ,
Ampelidæ,
Laniidæ,
Troglodytidæ,
Certhiidæ,
Paridæ,
Icteridæ,
Corvidæ,
all of which have already been described in the present work, with the
exception of the last two.
The family of Tanagers is peculiar to the New World, which abounds in
species of a great variety of forms. Only one genus, _Pyranga_,
actually enters within the limits of the United States, with four
well-marked species, there being many others in Central and South
America.