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. per spirilla tus 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. 
1. Fluvicola icterophrys. D'Orb. fy Lafr. Mag. de Zool. 1837. p. 59. 
Muscicapa icterophrys, Vieill. Encyc. Meth. p. 832. 
Le Suiriri noiratre et jaune, 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 moesta, Licht. Oat. p. 54-. 
Muscicapa nivea, Spix, Av. pi. 29. f. 1. 
Pepoaza nivea, D’Orb. ty 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 F£, 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 Azar^e. Gould. 
Plate X. 
F. alba; alis, caudd caudceque tectricibus atris, his albo-marginatis ; primariis Jlaves- 
centi-albis, basibus apicibusque nigris ; rostro pedibusque atris. 
Long. tot. 8 T 3 g- unc. ; alas, A-fy; caudoe , 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. 
