Bulletin - United States National Museum - si-pddr - Smithsonian ...

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52 BULLETIN" 133, UNITED STATES NATIONAL MUSEUM
hurried into dark corners; others attempted to clamber into the
lighted passageAvays, pulling themselves over the raised thresholds
of the doorways by aid of their bills. Occasionally one gave a
raucous call, with widely opened mouth. All resented handling by
biting savagely. Wlien thrown overboard they fluttered heavily
down to the water or turned to swing in again toward the ship.
One that I skinned proved to be an immature female, and all of
those handled appeared to be young birds. During the daytime
they were observed resting on the water or scaling over the waves,
when they were recognized by the light under wing coverts that
showed in contrast with their otherwise somber coloration.
PROCELLARIA AEQUINOCTIALIS AEQUINOCTIALIS Linnaeus
ProceUaria aequinoctialis Linnaeus, Syst. Nat., ed. 10, vol. 1, 1758, p. 132.
( Cape of Good Hope.
This species, noted commonly at sea from June 15 to 20, 1920,
from latitude 22° 30' S. to the mouth of the Rio de la Plata, fre-
quently came close to the stern of the steamer in following over the
wake. The birds circled with set wings, scaling swiftly along, often
tilting sideways at such an angle that they seemed about to overturn.
As their momentum slackened they rose again Avith a few
quick wing strokes, and then swinging in a short circle scaled away
once more. Occasionally they alighted on the water, where they
floated high like gulls. They were characterized by sooty black
plumage, rounded tail, and a bill marked with yellow and slaty
black. The silence of these great sea birds, in time, impresses one
as uncanny.
On November 3 and 4 many were circling just outside the breakers
below Cabo San Antonio, on the eastern coast of Buenos Aires,
during a heavy gale. At times they swung in to w^ithin 100 meters
of the shore. On a dead bird picked up on the beach at La Paloma,
Rocha, Uruguay, on January 23, 1921, the culmen measured 50.5 mm.,
while there was a small white interramal chin spot. The head of
this specimen was preserved.
OCEANODROMA TETHYS (Bonaparte)
Thalassidroma tethys Bonaparte, Journ. fiir Ornith., 1853, p. 47. (Galapagos
Islands.)
An immature female Galapagos petrel came aboard ship on the
evening of May 9, 1921, when we were about 10 miles west of La
Plata Island, on the coast of Ecuador. As Loomis^^ has indicated,
the tail in this species is slightly forked, the incision in the present
specimen amounting to 5 mm., so that tethys seems to belong in the
"Proc. California Acad. Scl., ser. 4, vol. 2, pt. 2, no. 12, Apr. 22 1918, p. 153.