the Province of Buenos Ay res. 173 



are of a more sombre plumage. Like S. luteola, many 

 move in a northerly direction in winter^ at which season both 

 sexes congregate in enormous flocks. On the 17th April of 

 this year I witnessed a vast migratory body of this species 

 whilst steaming down the riacho of Baradero. The flight 

 continued for upwards of an hour^ crossing the river from 

 south to north ; and during that time it was not possible to 

 look in any direction without seeing hundreds of birds. They 

 are a more tree-loving species than S. luteola, and, sometimes 

 at least, parasitical in their breeding-habits. On the 17th 

 October I took a nest with one egg from a nest of Furnarius 

 rufus, which the Finch had relined for its own use, and shot 

 the old male bird whilst standing in the doorway of its ap- 

 propriated home. A friend of mine has taken the eggs from 

 a nest of Synallaxis. An adult male shot on the 6th of April 

 is — total length 5'3 inches, beak 3, tarsus 6. Forehead bright 

 orange. Head above, neck above and on sides greenish yel- 

 low, centre of feathers darkest. Throat and neck below chest, 

 stomach, and under tail-coverts bright canary-yellow. Back 

 dark greenish yellow, centre of feathers nearly black. Upper 

 tail-coverts yellowish green. Primaries dark brown, all but 

 the first slightly edged with pale yellow ; first and third of 

 equal length, second rather the longest. The outer webs of 

 the second, third, fourth, and fifth become narrower towards 

 their extremities. Under wing-coverts canary-yellow. Tail 

 twelve feathers, nearly black, edged with yellow. 



An adult female, shot on the same day, is slightly smaller 

 than the male. Head, neck, and back dull brown, centre of 

 feathers darkest. Upper tail-coverts dark greenish brown. 

 Throat dirty white, with a tinge of yellow at the corner of 

 base of lower mandible. Chest light brown, with a tinge of 

 dull white. Stomach dull white, towards the sides light 

 brown. Flanks light brown. Under tail-coverts dirty white, 

 base of feathers with a tinge of yellow. Primaries dark brown, 

 slightly edged with pale yellow, chiefly on the inner webs ; 

 the basal half of the inner webs of these feathers is pale 

 primrose-yellow. Greater Aving-coverts dark brown, very 

 slightly edged with pale yellow ; lesser wing-coverts greenish 



