I918.] Cape San Anto?no, Buenos Ay res. 401 



136. Centrites niger (Bodd.). Red-backed Tyrant. 



Mr. Hudson and Mr. Grant describe all we know about this 

 species, which makes its appearance in our district in January 

 (viz. the middle of summer), from the 3rd to the 31st, usually 

 in the latter half of the month. By February it is very abun- 

 dant and generally distributed. In July it proceeds to take its 

 departure again, though a few remain through August and 

 so late as 7 September. Generally, it is shy of pedestrians, 

 though 1 have known one exception, when the bird re- 

 peatedly let me approach within three yards before taking 

 to flight. 



141. Hapalocercus flaviventris (d'Orb. et Lafr.). Reed- 

 Tyrant. 



Iris brown ; bill dark brown ; feet black. 



This dainty little Tyrant comes to us in October and leaves 

 again in April. Its habitat is invariably the grass-coverts of 

 dry swamps and the great beds of " Junquillo negro" on 

 this and the neighbouring Tuyu estancia, and consequently 

 it is not easily detected or observed. It possesses a sweet 

 clear call or note, as detailed by Mr. Hudson. 



The nesting-season is from the middle of November to 

 the middle of December. The nest, which is not easily 

 found, may either be attached to a few *■' Durasnillo" or 

 rush-stems in a dry swamp, or in a dense clump of " Jun- 

 quillo negro," at a height from the ground of a few inches 

 to three feet, more generally two feet. It is well and com- 

 fortably constructed of fine dry moss, and lined with delicate 

 dry grass and a few feathers. I have never found a clutch 

 of more than three eggs, and two is not an infrequent 

 number. 



The eggs are cream-coloured, and measure 18 X 14 mm, 



146. Serpophaga subcristata (Vieill). Small -crested 

 Tyrant. 



I would not call this species an abundant one in our 

 district, and the records in my diary all these years are not 



