376 
PROCEEDINGS OF THE ACADEMY OF 
through fuscescens and Holbollii , is gradual, we see not the slightest cause for 
separating it, even sub-generically. Moreover, if distinctions were founded 
upon size of bill, there is no reason why a similar discrepancy in the size and 
proportions of the feet should not be made the grounds of division, and thus 
it would be necessary to separate the A. canescens and exilipes ; — a procedure 
hardly warrantable. We think it probable that the genus, as far as can be 
judged from the species now known to compose it, is incapable of a natural 
division. 
Throughout this genus the most tangible evidence of immaturity, next to 
the absence of the rosy tints on the breast and rump, lies in the presence of a 
general yellowish or rufous suffusion, particularly about the head and fore- 
parts of the body. This is accompanied by a general indistinctness of outline 
of the streaks, the dusky being bordered with reddish, which fades insensibly 
into the white ground color. Indeed, we are of opinion that this rule is capa- 
ble of much more extensive application, embracing perhaps the greater part 
of the genera of the Fnngillidce the species of which are streaked. It is very 
evident in young specimens of Passerculus savanna , Poecetes gramineus , Melo - 
spiza melodia , and other allied species, and in some species of Plectrophanes , the 
females of which resemble the streaked sparrows very closely. Moreover, in 
some species, as for example, the Spizella socialis and Coturniculus passerinus, the 
presence of streaks below is an evidence of immaturity, these streaks entirely 
disappearing when the bird is fully adult. 
The “theory of variation,” then, in this genus, so far as regards the plumage, 
would seem to be essentially the same as that which is most usual throughout 
the family, though agieeing most closely with that exhibited by the Spizel - 
lince (of Baird, as defined by that author). The sexual variations, however, in 
the absence in the female, of the red which is the most conspicuous color of 
the male, is precisely the same as is seen in allied coccothraustine types, such 
as Pinicola , Carpodacus , Curvirostra , etc. 
Geographical Distribution. — The genus is entirely confined to the Northern 
hemisphere, being unknown in Africa'or South America. It is, moreover, em- 
phatically a boreal genus, all the species inhabiting high latitudes, and only 
coming south during the winter. The species, as far as now known, are very 
equally distributed. One is common to Europe and America; two are peculiar 
to America ; two to Europe ; and two inhabit the neutral ground of Greenland. 
Both the latter, however, are probably found at times in Europe, and may also 
very possibly be detected on our own continent. 
Comparison with allied Genera. — The genus is most closely allied to Canna - 
bina, a European form, with Fringilla cannabina Linn., as type, both having 
much the same general form and appearance. The differences, however, are 
readily appreciable, and quite sufficient to separate the two. In Linota the bill 
is much larger, stouter and more turgid, and less compressed and. acute, and 
the nasal plumuli are very much shorter. The feet are larger and stronger, the 
toes especially much longer, the middle one, without the claw, being nearly as 
long as the tarsus. The hind toe is as long as its claw. The tail is shorter, 
less forked, its feathers much narrower and more acute. The wings are much 
the same. The general pattern of coloration is the same; but the colors of the 
back are in well defined areas ; the throat is streaked ; the tail and wings with 
very broad well defined white edges, etc. Apparently the most essential dis- 
tinctive characters are those lying in the feet. Leucosticte is the most closely 
allied North American genus, agreeing with JEgiothus in many respects. It 
differs, however, in a stouter, more turgid, less compressed and acute bill, with 
its decidedly convex culmen ; in the presence of ridges on the lower mandible. 
The tail is much less forked, and the feathers are even broader, with more ob- 
tuse tips. The feet are much the same; but the lateral toes, in comparison 
with the middle, are shorter. The claws are shorter. Chrysomitris , with Frin- 
gilla spinus L., as type, has even a more compressed, attenuated and acute bill, 
but the culmen is much curved ; the nasal plumuli are exceedingly short; the 
[Nov. 
