BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 311 



KNIPOLEGUS CYANIROSTRIS (Vieillot) 



Muscicapa cyanirostris Vieillot, Nouv. Diet. Hist. Nat., vol. 21, 1818, p. 

 447. (Paraguay.) 



The present species was found at Las Palmas, Chaco, July 14 

 (male taken), and 30, 1920 (female secured), at San Vicente, Uru- 

 guay, January 28 (two males shot), 30 (female), and 31, 1921 

 (female), at Lazcano, Uruguay, February 6 (female), and at Rio 

 Negro, Uruguay, February 14 and 18. The seven skins preserved 

 offer no differences from others examined from Paraguay and south- 

 ern Brazil. The male of this species resembles K. ate7Ti7)ius in 

 color, but has the white on the wing restricted to a narrow margin 

 on the inner webs of the primaries. The female differs from that of 

 aternmus in being heavily streaked. The form of the primaries in 

 both sexes is normal. Specimens secured at Las Palmas are in full 

 winter plumage, while those shot in Uruguay, in midsummer, are 

 in molt. An immature female that has not quite completed the molt 

 into fall plumage is more rufescent above and less heavily streaked 

 below than adult females securt d in winter. 



In an adult male, taken July 14, the tip of the bill was black; re- 

 mainder pale Medici blue ; iris coral red ; tarsus and toes blgck. An 

 adult female, taken July 30, had the maxilla dull black; mandible 

 light Payne's gray, slightly darker toward tip; iris Rood's brown; 

 tarsus and toes black. 



In the Chaco these birds frequented dense growths of heavy forest, 

 while in Uruguay they were found in heavy thickets near water. 

 They Avere especiallj^ common in the low growth along the Rio Ce- 

 bollati, near Lazcano. They were silent and, save for the twitching 

 of the tail, were rather qui t, though alert and active in the pursuit 

 of insects on the wing. Their general appearance was that of a 

 phoebe iSayornis). The streaked females are so different in color 

 from the black males that they may easily be mistaken for another 

 species. 



KNIPOLEGUS ATERRIMUS ATERRIMUS Kaup 



Cnipolegus aterrimus, Kaup, Journ. fiir Ornith., 1853, p. 29. ( Cochabamba, 

 Yungas, Moxos, Chiqiiitos, Bolivia.'*) 



According to Berlepsch^^ Knipolegus anthracinus Heine, ^^ de- 

 scribed from Bolivia and in current use for birds from northern 

 Argentina, is identical Avith K. aterr'itnus of Kaup, since examina- 

 tion of the type specimen did not bear out the supposed character 

 of smaller size in aterrimus. I have seen no specimens from Bolivia, 

 but Berlepsch states that skins from Argentina and Bolivia are 



8« From d'Orbigny and Lafresnaye, Mag. Zool., 1837, p. 59. 



8' Proc. Fourth Int. Orn. Congr., 1907, p. 471. 



«s Cnipolegus anthracinus Heine, Journ. fiir Ornith., 1859, p. 334. (Bolivia.) 



