BIRDS. 53 



are quite differently marked. In L. erythropterus, the third, fourth, and fifth 

 primaries are the longest, and are equal to each other ; the second is only a little 

 shorter than the third. In L. perspicillatus the third is rather shorter than the 

 fourth and fifth ; and the second is proportionally shorter relatively to the third, 

 so that the outer part of the wing in this species is more pointed than in L. ery- 

 thropterus. The hinder claw in the latter is only in an extremely small degree 

 straighter than in the former ; and this, considering that the L. perspicillatus is 

 generally perched, and when on the ground, can only hop ; and that the L. ery- 

 thropterus feeds there entirely, and walks, is very remarkable. 



I. Fluvicola icterophrys. D'Orb. <Sf Lafr. Mag. de Zool. 1837. p. 59. 



Muscicapa icterophrys, Vieill. Encyc. Meth. p. 832. 

 Le Suiriri noiratre et jauno, Azara, No. 183. 



Specimens were found by me both at Monte Video and at Maldonado, on the 

 banks of the Plata. I found Coleoptera in their stomachs. 



2. Fluvicola Irupero. G. R. Gray. 



Tyrannus Irupero, Vieill, Ency. Meth. p. 856. 



Muscicapa mcesta, Licht. Cat. p. 54. 



Muscicapa nivea, Spix, Av. pi. 29. f. 1. 



Pepoaza nivea, D'Orb. $ Lafr. Mag. de Zool. 1837. p. 62. 



Irupero, Azara, No. 204. 



This elegant bird, which is conspicuous amongst most land species by the 

 whiteness of its plumage, is found, though not commonly, (in November) in Banda 

 Oriental ; whilst near Santa Fe, three degrees of latitude northward, it was com- 

 mon during the same time of year. It is rather shy, generally perches on the 

 branches of bushes and low trees. 



3. Fluvicola Azxrm. Gould. 



Plate X. 



F. alba; alis, cauda caudceque tectricibus atris, his albo-marginatis ; primariis jiaves- 

 centi-albis, basibus apicibusque nigris ; rostro pedibusque atris. 



Long. tot. 8y^ unc. ; aloe, 4^- ; caudm, 4 T 3 ^ ; tarsi, 1 ; rost. 1 . 



Head, all the upper and under surface white ; wings and tail black ; tail coverts 

 black margined with white ; primaries broad and crossed near their extremity 

 with sulphur white, and tipped with brown ; bill and legs black. 



Habitat, banks of the Plata. 



