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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 between
the lighter colored Nycticorax from Argentina north into
northern South America and that of North America. Doctor Chapman"
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).