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

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BIRDS OP ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 321
actively about through the trees. Their song was a low trill that
may be represented as chee-ee-ee-ee. No others were recorded.
The present species differs from S. subcristata and S. 7nunda,
which it resembles superficially, in the lack of black and white
markings in the crown. The bill in addition is longer than usual in
the other two species. The abdomen is white centrally, while the
sides and loAver tail coverts are washed with yellowish. It is distin-
guished at a glanc.^ from its allies.
SERPOPHAGA NIGRICANS (Vieillot)
Sylvia nigricans Vieillot, Nouv. Diet. Hist. Nat., vol. 11, 1817, p. 204.
(Paraguay and shores of the Rio de la Plata.)
The present species is somewhat rare at the present time, and was
found in few localities. At Berazategui, Buenos Aires, June 29,
1920, an adult female was taken on low ground near a ditch. The
bird was active in pursuit of insects and when quiet rested indiffer-
ently on low grass stems, twigs, lumps of mud, or level ground.
The feet were bedaubed with mud. In Uruguay the species was
found on three occasions, each time in lowland marshes where dense
thickets of low willows and other water-loving shrubs stood in
shallow water. One was observed February 3, 1921, at the Paso
Alamo on the Arroyo Sarandi. An adult male was taken February
7, and another seen on the day following near the Rio Cebollati
below Lazcano. A third, an immature female, was taken at llio
Negro, Uruguay, on February 18. The birds hop rather actively
about in their dense cover, jerking the broad black tail or nervously
spreading it like a fan even when at rest.
The adult male taken February 7 had the bill and tarsus black;
iris warm sepia; inside of mouth, including tongue, warm chrome.
The bird taken at Berazategui in June is in full winter plumage.
The one shot near Lazcano, February 7, is badly worn and is molting
on the body. It appears much darker than the winter bird.
The immature specimen taken, still in juvenal plumage, is browner
above and on the lower abdomen and under tail coverts than adults
and has no concealed white spot in the crown.
COLORHAMPHUS PARVIROSTKIS (Gould)
MyioMus parvirostris Gould, Zool. Voy. Beagle, pt. 3, Birds, July, 1839.
p. 48. (Santa Cruz, Patagonia.)
Near Concon, Chile, a male was secured on April 26, 1921, and
another on the day following. The first mentioned, when first
killed, had the maxilla and tip of mandible black; base of mandible
hair brown; iris chestnut brown; tarsus and toes black. The birds
were found near small streams where they sought low perches on
weeds or bushes in little open spaces, whence they made sallies