Here again we have the aberrant groups united by such birds as Setopkaga
rubra, Sw. *, where the form of the bill is completely that of an Accentor,- joined
to the remarkable and otherwise inexplicable character of a strongly-bristled
rictus. The analogies of the whole group are highly interesting, both in reference
to the external anatomy, and to the habits and economy of the living birds.
Contracting the sphere of our inquiries, we shall select, for the genus further analysis,
SYLVICOLA, Sw.,
as a group which more particularly regards the Warblers of North America.
lHiaerritei easgain we find three divisions, typically distinguished by the following pecuj
' Sub-genera.
l_y pic. al, group. J> Bill entire, acute, pointed, sub-conic . Vermivora ’ Sw’
v0s u,o -It ypi.c al, group. J> Bill obsoletely notched, slightlyJ bent
3* I Hind toe much stronger, and more length-
Aberrant group. |- ened; bill various
Sylvicola, Sw.
Dumecola, Sw.
Zosterops, H. and Y.
Mniotilta, Yieil.
The paucity of species in the two extreme aberrant types, viz., Dumecola and
Mniotilta, prevents us, at present, from knowing in what way they may be united.
We shall therefore state the affinities and analogies of the whole group more in
detail. The typical distinctions of the entire genus
SYLVICOLA
consists in the bill being lengthened-conic, either entire, or slightly notched remotely
from the tip of the upper mandible, which is scarcely deflexed; wings
pointed, the first quill nearly as long as the second.
The circular union of these groups must be explained more fully in another
place; for the present it is sufficient to state, that Wilson, more than twenty years
ago, clearly pointed out in what manner the worm-eating Warblers (Vermivora;)
differed from the true Sylvicola;, with which, nevertheless, all subsequent writers
have continued to blend them f. As yet we have actually seen but one species of
Dumecola, although we strongly suspect the Musicapa diops, PI. Col. 144, f. 1, is
* Synop. of Mexican Birds, No. 19.
T These birds have recently, indeed, been erroneously placed with the sub-genus Dacnis, belonging to the Cinny-
ridee. This resemblance between the two groups is certainly strong, but it is only analogical.—Sw.
another, connecting this form with Zosterops. The affinity of these white-ringed
Warblers to the Sylvicola;, we pointed out in characterizing the latter group*.
Finally, the Mniotilta pirns, Sw., or Pine Warbler óf Wilson, so completely resembles
the Vermivora solitaria, Sw., that several authors have actually mistaken
theL oent eu ss pneocwie sl ofookr tthoe tohteh earn fa.logies of this singular group.
Conirostres . Bill lengthened, conic, entire; rictus nearly smooth . . Vermivora.
D entirostes . Bill notched, somewhat remotely from the tip; rictus bristled . Sylvicola.
F issirostres . Bill depressed; feet weak;..;;,, v ■ • .Dumecola.
T enuirostres . Bill subulate towards the ehd; rictus smooth . . Zosterops.
Scansores . . Feet scansorial; hind toe and claw much lengthened . . Mniotilta.
In these five types of form, being the first assemblages of species—in other
words, the lowest denomination of groups in nature,—we have a typical representation
of every division in the whole class of AVES. It was no doubt the very
conic and sharp-pointed bills of the Vermivora; which induced M. Cuvier to think
they connected the Warblers with the Corurostres, by means of Icterus. The
remote notch and the bristled rictus are both characters common to a Shrike and a
Sylvicola ; and that the type of this form should have been ranked by Linnaeus as
a Parus, is immediately understood by that genus representing Sylvicola in its own
circle. Dumecola rujicauda, Sw., would pass for a Flycatcher, if its feet and
wings were not examined. The analogy between Zosterops and the Tenuirostres
is so perfect and beautiful, as to have deceived such accurate observers as MM.
Cuvier, Vieillot, Temminck, and Lesson. The Diceum choronotos, or Grimpereau
de H U de Bourbon, PI. Enl. 681,2, of these eminent naturalists, is, in fact, a true
Zosterops, and probably the type of the group. Sylvia Javanica is a second, and
several others have been also placed in the genus Diceum. In characterizing the
sub-genus Oxyglossus (not being aware it had previously received the name of
Mniotilta), we ourselves fell into the error of referring it to the scansorial creepers.
In this we were principally influenced by the example of M. Cuvier, who ranks
the Mniotilta varia as a Nectarinia. These relations, however, as well as every
other cited, while they establish the correctness of the above table of representatives
in the fullest manner, are nothing more than so many instances of analogy.
* Zool. Journ., ni., p. 169. f See Bonaparte's Observ. on Wilson's Nomenclature ; article Sylvia solitaria.