Paraguay, Bolivia, and Southern Brazil. 337 



197. Ardea sibilatrix. 



Ardea sibilatrix Arg. Orn. ii. p. 100. 



Syrigma cyanocephalum Sharpe, Cat. B. xxvi. p. 170. 



a. ^ ad. Tebicuari, Paraguay. Aug. 17, 1909. 



Irides pale bluish grey ; orbits and lores electric blue ; 

 bill lilac, tip black ; legs and toes black. 



This species was commonly observed on the river expedition 

 in most o£ the swamps, usually in pairs ; and, when 

 disturbed, perched on the outermost branches of the trees. 

 It has a low whistling note. 



198, BUTORIDES CYANURUS. 



Butorides cy amir us Arg. Orn. ii. p. 101. 



Butorides striata Sharpe, Cat. B. xxvi. p. 175 ; Gates, Cat. 

 Birds' Eggs Brit. Mus. ii. p. 126. 



a. ? ad. Rabicho, Brazil. Oct. 8, 1909. 



Irides rich lemon-coloured, orbits and top of lores greenish 

 yellow, rest of lores and adjoining gape dull sooty black ; 

 bill black, lower basal half of lower mandible greenish 

 yellow ; legs and toes ashy-yellow, lemon-yellow at tibio- 

 tarsal joints, behind tarsi, and soles of feet. 



Commonly observed on the river expedition and fre- 

 quenting the bush along the banks, usually singly. 



When alarmed this bird has a curious habit of raising 

 the feathers of the head and neck, and on taking wing it 

 utters a harsh grating cry. I did not obtain it in the Ajo 

 district, where it is very rare, though quite a numbei' were 

 observed there by jMiss Runnacles during the summer of 

 1909, and I have an adult male and two adult females 

 collected by her between October 24th and November 14th. 

 It also bred there that year, and eight eggs are in her 

 collection taken between November 9th and 28tli. 



These eggs are pale bluish green and measure : axis I'oO 

 to 1*55 in., diam. 1*1 to 1*19. 



Miss Runnacles tells me that the full clutch of eggs 

 consists of four, and that the nest is a small })latform of dry 

 durasnillo in a canadon. 



