70 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



Young. — Much duller in color than adults. Above dark sooty gray- 

 ish brown, the back (sometimes pileum also), blackish, ihore or less 

 glossed with bluish; under tail-coverts sooty grayish brown usually 

 margined with paler; rest of under parts white, the chest (forming a 

 more or less distinct band), sides and flanks pale wood brown or brown- 

 ish buff. 



Adult male.— Length (skins), 106-122 (115.1); wing, 92-100 (96.2); 

 tail, 48-65 (50.9), forked for 7-15 (11); exposed culmen, 5-6.5 (5.2); 

 width of bill at frontai antise, 4^5 (4.5); tarsus, 10-11 (10); middle toe, 

 9-10.5 (9.1)." 



Adult female.—Length (skins), 106-126 (113.3); wing, 91-102 (94.6); 

 tail, 47-54 (50.8), forked for 8-13 (10.1); exposed culmen, 5-6 (5.6); 

 width of bill at frontal antise, 4^5 (4.6); tarsus, 10-10.5 (10.1): middle 

 toe, 8-10 (9.2).* 



Costa iiica (San Jose, Tucurrique, Navarro de Cartago, Alajuela, 

 etc.) and southward over whole breadth of South America as far as 

 southern Brazil, Bolivia, and Peru (northern Chile? '^). 



Hirundo cyanoleuca Vieillot, Nouv. Diet. d'Hist. Nat., xiv, 1817, 509 (Paraguay; 

 based on Golondrina de los temoneUs negros Azara, Apunt., ii, 508). — Gkay, 

 Cat. Fissirostr. Birds Brit. Mus., 1848, 27.— Gould, Zool. Voy. "Beagle," 

 iii, 1841, 41 (Valparaiso, Chile, breeding) . — Leotaud, Ois. Trinidad, 1866, 

 90.— ScLATBE, Proc. Zool. Soc. Lond., 1867, 321. 



''Fourteen specimens. 



*Ten specimens. 



Specimens from different geographic areas average, respectively, as follows: 



The series is not a very satisfactory one, and I suspect that several of the specimens 

 are wrongly sexed. Such as it is, I am unable to make out a northern form (" var. 

 montana" of Baird). The single Chilean specimen (from Valparaiso) differs from 

 all the others in the decided greenish instead of violaceous steel blue color of the 

 'Upper parts, and very likely represents a distinct form. 



The Chilean bird may be a different form. (See remarks above. ) 



