182 



ORNITHOLOGY. 



chestnut-brown; head above and back bhick, with a bluish metaUic 

 lustre ; quills and tail brownish-black. Tkroaf, breast, and flanks, 

 pale chestnut; middle of the abdomen, and under tail-coverts white, 

 the latter tinged with very pale chestnut. Bill black ; feet lighter. 

 " Irides dark-brown" (Gosse) . Some of the feathers of the back edged 

 with white. 



Young (specimen from Peru, which is //. riiflcoUaris, Peale). Upper 

 parts same as in the specimen described above, but with the chestnut 

 of the forehead nearly obsolete. Throat dull white; band across the 

 breast and flanks pale chestnut; abdomen white ; under tail-coverts 

 dull white, tinged with pale chestnut, and with large subterminal 

 spaces of dark-brown. " Bill black ; feet dusky ; irides brown. Male" 

 (Peale). 



According to Mr. Peale, the specimen in the collection of the Ex- 

 pedition was killed near Callao, Peru, on the twelfth of July. 



The two specimens now described, though presenting some differ- 

 ences in the colors of the under parts, we regard as of the same species, 

 and which is regarded by all late ornithologists as the true Hlrunclu 

 fulca of Vieillot. Both sufficiently resemble the figure in Ois. d'Am. 

 Sept. in all respects, except that the tail is there represented as forked, 

 but very probably erroneously by the artist, as it is not so stated in 

 the description. 



The difference in the colors of these two birds is not greater than is 

 usual in specimens of many species of the family Ilirnndiuidce, and 

 particularly in those like the common Hinindo rustica of Europe, or 

 the Hlrundo nifa of North America, having the under parts more or 

 less of a chestnut color. In Petroclielidon lunifrons, a well-known spe' 

 cies of the United States, and considerably resembling the bird now 

 before us, there is also much diversity in the extent and shade of the 

 chestnut color of the throat, though in adult specimens, it is nearly 

 confined to that region. In young and immature birds it is quite ob- 

 scure, and extends to the breast, mixed and shaded with pale brown. 



This bird has been mistaken for Hirundo lunifrons, Say, of North 

 America, by several authors on American Ornithology, and its name 

 has accordingly been applied to that species erroneously (as in Audu- 

 bon's Ornithological Biography, Y, p. 415). The two species strictly 

 belong to the same group, which is probably subgeneric only, but are 

 so different as to be distinguished with no difficulty on comparison. 

 Hirundo lunifrons is the larger, and may always be recognized by its 



