'mh'tj 



PETROCHELIDON. 



289 



(lulness of tho frontal band. There is no appreciable difference in 

 the sexes?. 



A specimen in Mr. Lawrence's collection, from Panama, I cannot 

 distiiigui.sli, except in being sm, Her. Length, 4.80; wing, 4.10; 

 tail, 2.10. The forehead is nearly white, as usual in lunifrons.* 



Summer specimens from the souther". Rocky Mts. (Los Pines, 

 N. M.) and Carlisle are considerably smaller than those from Fort 

 Bridger. 



Specimens in the collection from throughout the whole United 

 States to northern border, as also — 





' Petrochelidon . 



fHirumlo americann, Gmbun, S. N. I, 1788, 10i7 (from Baffon, VI, 65^8, 

 La Plata). — Petrochelidon americann, Cab. Mus. Hein. 1850-1, 47. 



fHirundo pyrrhonota, Vieill. Encycl, Meth. II, 524 (Azara, Apuiit. II, 

 511, no. 305, Paraguay). — Cuiyle p. Buum. Reiae La Plata, II, 1861, 

 477 (Tucuman). 

 Hah. Brazil ? Paraguay f - 



In Mr. Lawrence's collection is an immature bird (No. 148, from Brazil), 

 much like corresponding stages of P. lunifrons, but differing in considerably 

 smaller bill, and in the lower tail coverts being much shorter (falling three- 

 quarters of an inch short of the tip). The rufous of the rump extends further 

 up the back, and there is a decided wash of reddish over the bre&at and belly, 

 sides and crissum, leaving only the abdominal region pure white. The frontal 

 band is not fully developed, but seems as if it might be whitish ; there is a 

 blackish spot on the lower throat, and a few whitish feathers in the chin. The 

 chestnut of the throat is lighter than in lunifrons, or of about the same shade 

 as that of rump. I think there is no doubt of its being quite distinct from 

 luiiifroui or swaimoni, but in its still immature condition cannot venture to 

 identify it. There are two names to which it might be referred, the //. ameri- 

 cana, of Gmelin — P. americann. Cab. M. Hein. I, 47 — (based on Ilirondelle a 

 cmtplon roiix, etc. (from the La Plata), Bdffon, Ois. VI, 698, La Plata) — 

 which, however, appeal's much too large — and llirundo pyrrhonota, Vieill. 

 Encycl. II, 524; Azara, Apunt. II, 511, Bonnine ed. 104; Cotyle pyrrhonota, 

 Burm. La Plata, II, 477. This is de8cribe4 by Azara as having black crissum ; 

 Bnrmeister, however, says this is grayish, edged with rusty whitish ; the fore- 

 head, lores, cheeks, and rump rusty brownish-red ; fore-neck, breast, and belly 

 ash gray, washed with yellowish, and tinged with reddish about the anus. 

 Length, 5". Wings, 4". 



Buffon speaking of his Ilirondelle. a croupion roux et queue ca, '■>. describes 

 it as brownihh-black above, with green and blue reflections ; ruu ifous, the 

 feathers edged with whitish ; under parts dull white, the lower tail coverts 

 rufous. Another specimen is said to have a rufous throat. No meution is 

 made of a black spot on the Jugulum, or of a frontal band. 



19 ^May, 1865. 



