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BIKDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 111
Ancles in Mendoza. and again in Tucuman, but identity of these
birds is often uncertain, even when specimens are available, and I
do not care to hazard a guess as to what they may have been. The
question of species and subspecies in the South American representa-
tives of the genus Buteo is much involved and can be made clear
only by collection of extensive series throughout the continent.
According to Stresemann,®** Buteo erythronotu^ (King)^^ becomes
Buteo folyosoma (Quoy and Gaimard).
BUTEO SWAINSONI Bonaparte
Buteo sicainsoni Bonaparte, Geog. and Comp. List, 1838, p. 3. (Near the
Columbia River.)
On April 17, 1921, a Swainson's hawk was soaring in company
with other hawks over the summit of the Sierra San Xavier above
Tafi Viejo, Tucuman.
GERANOAETUS MELANOLEUCUS (Vieillot)
Spizaetus melanoleucus Vieillot, Nouv. Diet. Hist. Nat., vol. 32, 1819,
p. 57. (Paraguay.)
Near the city of Mendoza this species was seen on March 13, 1921,
and above Potrerillos one, that had perhaps been captive at some time
as a string dangled from its leg, was observed on March 16. Sev-
eral were found in company with smaller hawks, soaring over the
Cumbre above Tafi Viejo, Tucuman, on April 17. When awing the
tail of this bird appears strongly rounded.
RUPORNIS MAGNIROSTRIS PUCHERANI (J. and E. Verreaux)
Asturina Pncherani J. and E. Vekkeaux, Rev. Mag. ZooL, ser. 2, vol. 7,
1855, p. 350. (Paraguay.")
From available material it seems that this subspecies is characterized
by the dark, almost black throat (in the adult), very narrow
rufescent bars of the undersurface, slight longitudinal stripes on
foreneck and upper breast, and by the rufescent tinge of the lighter
bars in the tail. Two adult females collected at Las Palmas, Chaco,
on July 26 and 28, 1920, agree with specimens examined from Paraguay
in these particulars. An adult female from San Vicente,
Uruguay, taken on January 31, 1921, is not wholly in agreement
with pucherani, as it has the heavier barring on the undersurface
found in B. tri. nattereri, but in other respects is more like the present
^ Journ. fur Ornith., 1925, pp. 309-319.
^ Haliaeetus erythronotus King, Zool. Journ., -vol. 3, 1827, p. 424. (Port Famine,
Straits of Magellan.) No locality is cited in connection with the original description,
but on p. 426, in closing his account of the hawks secured. King remarks that " all
of the above species of Falconidae were collected at Port Famine." See also Swann,
Syn. Accipitres, pt. 2, Jan. 3, 1922, p. 85.)
"^Type locality designated by Brabourne and Chubb, Birds of South America, vol. 1,
December, 1912, p. 68.