54 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



This bird is very common in the neighbourhood of Maldonado, where it 

 frequents the open grassy plains. It sits on the top of a thistle, or on a twig, 

 and catches the greater part of its food on the wing. It is generally quiet in its 

 movements and silent. Mr. Gould remarks, that he finds "nearly all the species 

 of this peculiar group to differ remarkably in the structure of their wings and 

 tail, while in all other respects they closely resemble each other both in form and 

 habit ; I have, therefore, hesitated to separate them into so many genera. I have 

 assigned the present species to Mr. Swainson's subgenus Fluvicola, considering 

 that differences in the form of one organ alone would not be sufficient grounds 

 for the institution of a new genus among such closely allied species ; the present 

 bird evidently leads off to Tcenioptera, a genus proposed many years since, by 

 the Prince of Musignano for the Pepoazas of Azara. 



" This species is closely allied to, if not identical with the Pepoaza Do- 

 minicana of Azara, but as there is a degree of obscurity in his description, which 

 causes some doubt on this point, I have considered it better to pay a just 

 tribute of respect to that zealous labourer in the field of natural science, by 

 assigning his name to this very elegant bird." 



1. Xolmis CORONATA. G. R. Gray. 



Tyranuus coronatus, Vieill. Eucy. Meth. p. 885. 

 Muscicapa -vittiger, Licht. Cat. p. 54. 



My specimen was obtained on the wooded banks of the Parana, near Santa 

 Fe, in Lat. 31° S. 



Boie's name of Xolmis is adopted by Mr. G. R. Gray, as it was proposed 

 some five years anteriorly to that of the Prince of Musignano's. 



•2. Xolmis nengeta. G. R. Gray. 



Lanius nengeta, Linne, 1. p. 135. 7. 



Tyrannus nengeta, Swains. Journ. Sci. xx. p. 279. 



Fluvicola nengeta, Swains. Nat. Libr. Fly-catchers, p. 102. pi. 8. 



Tyrannus pepoaza, Vieill. Ency. Meth. p. 855. 



Muscicapa polyglotta, Licht. Spix. II. pi. 24. 



Tyrannus polyglot tus, Cuv. 



Le Pepoaza proprement dit, Azara, No. 201. 



My specimen was procured at Maldonado, north bank of La Plata, where 

 it is not common. Its habits in many respects are like those of the Fluvicola 

 Azarce ; it appears to catch its prey on the wing. Iris bright red. 



