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

296 BULKETIN 133, UNITED STATES NATIONAL. MUSEUM
otherwise resemble adults. These birds are in molt from juvenal
to first winter plumage.
Near Concon, Chile, the large Agriornis was common from April
24 to 28, 1921. The birds Avere found on open flats near the Rio
Aconcagua, or in pastures dotted with bushes on the hill slopes
above, where they rested quietl}^ on the top of some bush that offered
outlook. Occasionally one dropped down to the ground where, like
a robin, it ran rapidly along for a few steps and then paused ab-
ruptly with head thrown up and body erect. The long, heavy bill
marked them from other birds of similar size, even at a distance.
All were silent.
In the adult male of this species the tenth primary is abruptly
narrowed at the tip for 10 to 16 mm., while the tip of the ninth is
narrowed for about half the amount of the tenth. In females the
primaries are normal. In the male taken at Concon the primaries
resemble those of the female. Apparently this sexual distinction
does not develop until the primaries have been molted once, so that
the wing of males in their first winter is like that of females.
The male shot April 24 had the maxilla dull black ; mandible light
drab, shaded with deep quaker drab toward the tip; iris anny
brown; tarsus and toes, dull black.
AGRIORNIS STRIATA STRIATA Gould
Agriornis striaius Goulu, ZooI. Voy. Beagle, pt. 3, Birds, 1839, p. 56.
(Santa Cruz, Argentina.)
Specimens of the present species secured number three, an adult
male from General Roca, Rio Negro, taken November 29, 1920, an
adult female from Zapala, Neuquen, shot December 7, and a male
from Tunuyan, Mendoza, collected March 27, 1921. The two summer
birds are in somewhat worn breeding dress, while the fall skin
is in full winter plumage. The female has the two outermost pri-
maries very slightly sinuated on the outer margin. In adult males
the ninth and tenth primaries are narrowed distally, and are incised
deeply for 12 to 16 mm. at the tip, this incision being only slightly
less on the ninth than on the outermost primary. The form Agriornis
s. andecola^^ of which I have seen no specimens, is said by
Berlepsch ^* to differ from tlie typical bird in having fainter brown-
ish black throat stripes and a stronger buffy wash on the lower
surface. It ranges in the higher Andes of western Bolivia.
Near General Roca, Rio Negro, these flycatchers were encountered
on November 29, 1920, and again on December 2, in a region of arid
gravel hills covered with an open growth of low brush. They often
''^ Pepoaza andecola d'Orbigny, Voy. Amer. Merid., vol. 4, pt. 3, Oiscaux, 1835-1844,
p. 351. (5,000 meters above the sea, in Bolivia.)
^^Proc. Fourth Int. Ornith. Con