BIRDS OF ARGENTINA, PARAGUAY, URUGUAY, AND CHILE 55 



men is white. This specimen measures as follows (in millimeters) : 

 wing, 289; tail, 105.5; exposed culmen, 65.7; tarsus, 80. The status 

 of the South American night herons is at present obscure, but so far 

 as I can determine from available material there is no distinction be- 

 tween the lighter colored Nycticorax from Argentina north into 

 northern South America and that of North America. Doctor Chap- 

 man" recently has recognized N, n. tayazu-guira (Vieillot) as a valid 

 race, while Hartert"^ has considered it a synonym of naevius. The 

 latter course is the one here followed. 



The night heron, known as the sorro de agua (water fox), had 

 the habits usual to the species in other regions. On the pampas, 

 where growths of rushes formed extensiA'e cover in lagoons and 

 swamps, they were fairly common. In Uruguay they were observed 

 in wooded swamps. None were seen in the Chaco. The species was 

 recorded as follows : Lavalle, Buenos Aires, October 31 and Novem- 

 ber 9, 1920; General Roca, Rio Negro, December 3 (one very light 

 and one very dark bird observed) ; Carhue, Buenos Aires, December 

 15 to 18; San Vicente, Uruguay, January 31, 1921; Lazcano, Uru- 

 guay, February 7 ; Rio Negro, Uruguay, February 16 to 18 ; Guamini, 

 Buenos Aires, March 3 ; Tunuyan, Mendoza, March 26 and 28. 



BUTORIDES STRIATUS CYANURUS (Vieillot) 



Ardea cyanura Vieillot, Nouv. Diet. Hist. Nat., vol. 14, 1817, p. 421. 

 (Paraguay.) 



Though Todd*^ considers variation in this species individual and 

 recognizes no subspecies, the adult green heron of southern South 

 America in the series that 1 have seen may be distinguished from 

 that of the northern portion of the continent (including Venezuela, 

 Colombia, and the Guianas) by paler, less grayish abdomen. Imma- 

 ture birds have the streaks on the foreneck heavier and the throat 

 more heavily spotted with black in the median line than those from 

 northern localities. Vieillot 's name, Ardea cyanura^ based on Aza- 

 ra's account of this heron in Paraguay, is available for this southern 

 subspecies, of which I have seen specimens from northern Argen- 

 tina, Uruguay, and Paraguay. 



Cancroma grisea of Boddaert,** referring to the Crabier de 

 Cayenne of Daubenton, which has Surinam as its type locality, 

 must be considered a synonym of striatus. Ardea noevia J. F. 

 Miller*' and Ardea naevia Shaw**' seem to represent a North Ameri- 



"U. S. Nat. Mus., BuU. 117, 1921, pp. 51-.54. 



«Bull. Brit. Orn. Club, vol. 35, Oct. 14, 1914, p. 15. 



*' Ann. Carnegie Mus., vol. 14, 1922, p. 136. 



" Tabl. Planch. Enl. Hist. Nat., 1783, p. 54. 



"•Var. Subj. Nat. Hist., no. 6, 1782, pi. 35. 



*« In J. F. Miller. Cim. Phys., 1796, p. 70 (pi. 35). 



