BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 73 



probable that with extensive material two or more forms may be 

 separated. 



COSCOROBA COSCOROBA (Molina) 



Anas Coscoroha Molina, Sasg. Stor. Nat. Chili, 1782, p. 234. (Chile.) 

 The coscoroba was first observed on November 15, 1920, at the 

 raouth of the Rio Ajo, Lavalle, Buenos Aires, when four passed in 

 companj' with flamingos. Other white birds that I took to be this 

 species were noted occasionally flying across the marshes, but none 

 came Avithin gun range. On January 31, 1921, at the Laguna Cas- 

 tillos, near San Vicente, Uruguay, I found a considerable number 

 gathered on open shores with Cygnus Tnelancorifhus. The white 

 coloration of these fine birds, especially when massed in flocks, made 

 them conspicuous at long distances, and they were correspondingly 

 v^ary. Before I was able to creep up within 100 meters the flocks 

 flew out a meter into the lagoon, and then swam away over the high 

 waves out of range, to return when I had passed. At rest they ap- 

 pear entirely white, but as the wings are extended the black at the 

 tips of the primaries is revealed. The bill appears to be light red- 

 dish in color. No specimens were taken. 



DAFILA SPINICAUDA (Vieillot) 



Anas spinicauda Vieillot, Nouv. Diet. Hist. Nat., vol. 5, 1816, p. 135. 

 (Buenos Aires.) 



Six adults of the southern pintail were collected near Lavalle in 

 Buenos Aires as follows? One female on November 2, 1920, another 

 on November 3, and three males and one female on November 6. An 

 adult male taken November 2 was preserved as a skeleton. In addi- 

 tion to the usually recognized characters of longer tail and greenish 

 black speculum used to distinguish males from females, it may be 

 noted that in females the throat is so nearly immaculate as to ap- 

 pear almost white, while in males it is strongly spotted. In a small 

 series of these birds from Chile, Argentina, Paraguay, and Peru, 

 I am unable to detect differences in size or coloration that may be 

 correlated with geographic range. 



An adult secured at Lavalle had the soft parts colored as follows : 

 Stripe down culmen nearly to nail, nail and margin of maxilla ad- 

 jacent, serrate margin of bill, and tip of mandible including nail, 

 black; space behind nail on maxilla and mandible gray number 7; 

 rest of bill mustard yellow; iris Vandj^ke brown; tarsus and toes 

 olive gray, clouded on joints with neutral gray; webs slate color. 



The coloration of young in the down, less than a week old, taken 

 from one of four specimens secured at General Roca, Territory of 

 Rio Negro, on November 27 is as follows (Cat. No. 283,675, U.S.N.M. 

 male) ; forepart of crown buffy brown, becoming clove brown, mixed 



