Tribes of
I n sesso res. Analogies. Sub-families of
Sylv’iÀdæ. Typical Genera,
f Bill much compressed; feet adapted both I CONIROSTRES . j for walking and perching; wings
l lengthened. j
r Sylvianoe. Sylvia.
I Bill stronger, notch more distant; wings 'I
D en t ir o st r e s . ■ j more rounded; claws larger, very r Philomelince. Philomela. [ acute. ... ... ; . . )
F issir o str es , Bill depressed, bristled at the base. Saxicolinoe. Saxicola.
T en u ir o st re s . Bill very slender ; rictus smooth.- Motacillinoe. Motacilla.
ScANSORES . .f Bill entire, or nearly so; hind toe 1
[ lengthened. I Parianoe. Parus.
On duly investigating this table, the ornithologist will detect many relations
of peculiar interest, which we cannot at present dwell upon. The two first,
indeed, are so faint, in comparison with the three last, that we do not feel perfectly
sure whether having now traversed over one half of the Dentirostral
circle,—the analogies of the typical groups are not reversed; in other words,
whether the Philomelince do not represent the Gonirostres through the medium of
the Merulinm ; and the Sylvianas the Dentirostres through the medium of the
Myotherinas ; but this will not in the least affect the progression as here exhibited. of the affinities
It will be sufficient, for our present purpose, to intimate the probable situation
foafm siulyc ho fspecies as are subsequently described. It is singular that in the subSAXICOLINi
®,
only one form has hitherto been discovered in the whole extent of America ; this
is typically represented by the well-known “ Blue bird” of Wilson, the Sialia
Wilsomi of our Mexican Synopsis. Another species, our Sialia Mexicana *, is
found on the table land of Mexico; and a third, still more distinct, was first discovered
in these expeditions. The intimate connexion between this group and
our European Robin, must be so evident to all who have perused the pages of
Wilson, that we are justified in viewing it as a sub-genus, or the American type
of Erythaca, Sw.; the Australian form is given in Petroica, Sw.; the African
* Sia l ia Mexicana, Sw.—Size of S. arctiea ; upper plumage bright purple-blue, chin and throat the same; across
the breast a rufous band, which colour is continued on the sides and flanks; middle of the body, vent, and under tail
cToavyelrosr ’sli gcohltl-ebcltuioen,. -inclining to white. Total length 6£, wings 4-J, tarsi f, tail 3 inches. Inhabits Mexico. In Mr.
is probably the Muscicapa stellata, Vieil.; and the Muscicapa longipes of M.
Lesson; seems to be the Oceanic form. The genus, thus indicated, stands aberrant
in its own sub-family, and appears to be the Fissirostral type of the Saxico-
lince. But as the sub-genera require much more study than we have yet had the
means of bestowing upon them, we rather wish the above series to be looked on
as questionable, or at least as unsupported by analogical demonstration.
Of the next aberrant division, comprising the
MOTACÏLLINÆ,
or Wagtails, America is equally destitute ; while the group itself is so deficient in
species, that its internal affinities are very obscure. The situation of Anthus, indeed, is perfectly evident ; it is the Tenuirostral type, and leads immediately to
Alauda; but that of Seiurus is particularly perplexing : it may, in fact, be questioned,
whether its precise situation is not on the confines of the next, rather than
of this sub-family. Be this as it may, the affinity of the two divisions is rendered
unquestionable, by comparing the short-clawed Anthi with Seiurus aquaticus, and
Seiurus aurocapillus with Accentor. The fissirostral type of the Motacillinoe,
hitherto undiscovered, will clear up much of this uncertainty.
The next and last aberrant division, comprising the
PARIANÆ,
is one of most peculiar interest, not only to the American ornithologist, as containing
nearly all the beautiful little warblers of that continent, but to the more
philosophic investigator of the natural system. This division, in fact, is the most
numerous, and consequently the most varied of the whole family; it accordingly
offers the best field for the investigation of those principles of natural arrangement
upon which our peculiar views are founded. Its internal arrangement may be
thus stated:—
Typical group. | Bill short, strong, conic, entire
Sub-typical group.
Bill more lengthened, and slender,
sub-conic, entire, or obsoletely
notched.
3.
Aberrant group.
Feet more especially adapted either
for perching, walking, or climbing ;
bill various.
Genera. Analogies.
Parus. CONIROSTRES.
Sylvicola. D e n t ir o s t r e s .
Setophaga. F is sir o st r e s.
Trichas. T en u ir o st re s.
Accentor. S cansores.
2 D 2