f 



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 molt- 

 ing 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 



