62 Mr. H. Durnford on the Birds of 



21. Thamnophilus argentinus. Cab. ; Ibis, 1377, p. 183. 

 The nest of this bird is a very slight flimsy structure of 



grass, lined with the finer fibres of the same material and a 

 little hair. It is placed about three feet from the ground, 

 and suspended from the twigs of a bush, which pass through 

 some portion of the nest, and is situated in reed-beds and 

 swampy places. 



22. Heleothreptus anomalus (Gould) ; Nomencl. p. 97. 

 On the 31st March 1877 I was given this bird, shot the 



previous day near Quilmes. It is the only specimen I have 

 seen here, and the museum does not possess an example. My 

 friend informed me that he flushed it from a clump of thistles. 

 Its stomach was full of insect-remains, and on dissection it 

 proved a female. 



[It is a female of the rather rare Caprimulgine form Heleo- 

 threptus anomalus, which we have not previously seen from 

 so far south. Natterer obtained it in several localities in 

 Southern Brazil (see Pelzeln, Orn. Bras. p. 12) . — Edd.] 



23. Picus MiXTUs, Bodd.; Nomencl. p. 99. 



Partially resident, but more numerous in the summer than 

 the winter. The male is rather more brightly coloured than 

 the female, and the red feathers on his head are more nu- 

 merous than in the other sex. 



24. BuTORiDEs cYANURus (Vicill.) ; Nomencl. p. 125. 

 Though I have never shot this bird I have often observed 



it in reed-beds near Lujan bridge, and less frequently at Punta 

 Lara. It frequents the same sort of places as Ardetta invo- 

 lucris and Nydicorax obscurus, though it is not nearly so 

 numerous as either of these birds, and, owing to its shyness, 

 I have not yet been able to obtain a specimen. 



25. Ardetta involucris (Vieill.) ; Ibis, 1877, p. 189. 

 On the 29th October 1876 I found a nest of this bird in a 



small lagoon amongst a clump of tall rushes, and just above 

 the water. It was entirely composed of short pieces of these 

 rushes, arranged with their points meeting in the centre, and 

 not more than seven inches in diameter, altogether a very 



