sometimes affinities; but as the fact has hitherto not been clearly observed, so the
principle of this variation remains to be discovered. It is generally seen in aberrant
groups; although not unfrequently, as in this instance, in such as are strictly typical.
To cite another instance, we may remark, that in the superb collection of Indian birds
at the Royal Museum of Paris, are several skins of Timalia pileata, Horsf., from
Sumatra and Java; of which some have the bill perfectly entire, some slightly, and
others distinctly notched; all, apparently, being old birds, full plumaged, and not
differing in the slightest degree in other respects. It will subsequently be seen
that this species stands in a group where the bill is either notched or entire *.—Sw.
[9 ] 3. F a l c o s p a r v e r i u s . (Linn.) Little Rusty-crowned Falcon.
P
Ge n .u s . Falco. L in n . A u c t o r u m .
L ittle Falcon. P e n n . Arct. Zool-, ii., p. 211, No. 110.
American Falco sparverius.Sparrow- L hawk.a t h . Ind., (F. sparverius.)i., p. 42, sp. 99. W il s o n , ii., p. 117, pi. 16,| f. 1. Female; and iv., p.
57," pi-. 32, f. 2. Male.
Falco sparverius, B u o n a p. Syn., p. 27, No. 10. V ig o r s . Zool. Joum., No. xi., pp. 425, 435.
Peepeekeeshees. Cr e e I n d ia n sla te x x iv . M a l e .
Prince Charles Buonaparte has separated the small American Falcons from the
larger kinds, characterising the group by wings shorter than the tail, and scu-
tellated tarsi. The latter character is only partially correct; for, in F. sparverius,
there are but three shield-formed transverse scales on the tarsus adjoining to the
toes, the rest of it being covered anteriorly by two rows of scales in alternate order,
forming a near approach to reticulation. In F. aesalon the tarsus is still more reticulated,
but it also is furnished with three shield-formed scales on its lower extremity.
The group, however, seems to be a natural one, the birds composing it
differing somewhat in their manners from the larger Falcons, and having analogies
in their habits with the Shrikes. The three small American Falcons that came
under our notice agree in having long tails, and in the first quill feather being a
little shorter than the fourth, or, at most, only equal to it,—both being considerably
shorter than thé second, which, again, scarcely exceeds the third one. The
rapidity with which the quill feathers decrease in length after the fourth, still renders
the wings pointed, yet not so much so as in the two larger species which we
* The whole of the groups in-this family require a thorough revision, not in the library, but in the museum ; and
until this is done, it is impossible to make full use of the distinction pointed out by Baron Cuvier, or to understand its
bearings.—Sw.