iyo BIRDS OF LA PLATA 



It is quite common in Buenos Ayres, and probably 

 has a partial migration, as it is most abundant in 

 summer* In its habits it closely resembles the species 

 last described, being always found in pairs, living 

 in thickets, where they hop incessantly about, ex- 

 ploring the leaves for small caterpillars, and always 

 conversing in low chirping and twittering notes. 

 They also sing together a little confused song. The 

 nest is fastened to the slender twigs of a low bush, 

 and is a deep cup-shaped and beautiful structure, 

 composed of a great variety of soft materials bound 

 together with spiders' webs, the interior lined with 

 feathers or vegetable down, and the outside covered 

 with lichen. The eggs are two, bluntly pointed, and 

 cream-colour. 



LITTLE RIVER-SIDE GREY TYRANT 



Serpophaga nigricans 



Above dull brownish cinereous ; wings and tail blackish, the coverts 

 and outer secondaries with slight edgings like the back ; crest slight, 

 with a well-marked white basal spot ; beneath paler and rather purer 

 cinereous; under wing-coverts pale cinereous; bill and feet dark 

 horn-colour ; length 4.7 inches. 



THIS species differs markedly in habits, language, 

 and appearance from the last. In both sexes the 

 colour is a uniform slatey grey ; the tail, which the 

 bird incessantly opens and flirts like a fan, is black ; 



