tipped with white, their bases irregularly barred with transverse marks of
brown and white. Under surf ace.—Cttm, throat, breast, belly, thighs, under
tail-coverts, under lining of wings, and edge of shoulders perfectly white.
On the flanks, however, there are some brown feathers irregularly interspersed
; and on the lower part of the breast, most of the feathers show
a most obscure margin of pale brown. Bill horn-colour. Cere and tarsi
yellow.
X?0KM.—Cere and nostril as in the M. Leucurus, but tlie bill not quite so
strong. Feathers on the sides and hack of head narrow and rather stifi';
those on the shoulders obtusely pointed,—which character of plumage is very
general in this sub-family. Wing: fourth primary very little longer than
the third or the fifth, which are equal to each otlier. First primary three
inches shorter than the fourth or longest, and more nearly equal to the
sixth than to the seventh. Extremity of wing reaching to within about an
inch and a half of the tail. Tarsi reticulated, with four large scales at the
base : upper part covered with plumose feathers for about three quarters of an
inch below the knee ; but these feathers hang dowm and cover nearly half of
the leg. Middle toe with fifteen scales, outer ones with about nine. Claw'S
of nearly the same degree of strength, curvature and breadth as in Polyborus
Brasiliensis, or in 31. leucurus, but sharper than those of the latter.
Hind claw measured in straight line from
tip to r o o t ...................................................
Claw of middle toe, a twentieth less than that
of the hind one.
Total length ..............................................20^
Tail ..............................................................9
Wings when f o l d e d ...................................... 15f
From tip of hcak to anterior edge of eye . ä
Tarsus from soles of feet to knee joint . 3^
Habitat, Santa Cruz, 50” S. Patagonia. {April.)
Mr. Gould, at the time of describing this species, entertained some doubts
whether it might not eventually prove to be the Phalcobwnus montanus of D'Orbigny,
in a state of change. I have carefully compared it with the description of the
P . montanus, and certainly, with the exception of the one great difference of
31. albogularis having a wdiite breast, whilst that part in the P . montanus is
black, the points of resemblance are numerous and exceedingly close. The
31. albogtdaris, appears to be rather larger, and the proportional length of the w'ing
feathers are slightly different; the cere and tarsi are not of so bright a colour;
the middle toe has fifteen scales on it instead of having sixteen or seventeen.
The black shades of the upper surface are pitchy, instead of having
an obscure metallic gloss, and the feathers of the shoulders are terminated
with brown, so as to form a collar, which is not represented in the figure of
d 2