528 Annals of the Carnegie Museum. 



datre peu brillante (bleu violet fonce chez S. cyanifrons). Les supra- 

 caudales cuivre-rougeatre (noires corarae les rectrices et tres finement 

 bordes de bronze chez S. cyanifrons'). Le dessous du corps d'un vert 

 dore plus jaune, le bee plus longe, 20.5 mm. (chez S. cyanifrons de 

 16 a 17 mm.). 



Therefore it is very evident that Amazilia alfaroatia Underwood is 

 a northern race of Sancerottia cyanifrons Bourc. & Muls., from which 

 it is to be distinguished by the crown being dark greenish-blue instead 

 of violet-blue ; the upper tail-coverts dark reddish instead of blackish 

 with narrow borders of bronze ; by the under parts being yellowish 

 golden-green ; and by its longer bill (20.5 instead of 16 to 17 mm.). 



243. Saucerottia niveoventer (Gould). 



Trochilns (- ?) niveoventer Gould, P. Z. S., 1850, 164 (David, Chiriqui). 



Amazilia niveiventris Ridgway, Proc. U. S. Nat. Mus., Ill, 1880, 319 (Costa 

 Rica). — Zeledon, An. Mus. Nac. de C. R., I, 1887, 122 (Costa Rica). — 

 Salvin, Cat. Birds Brit. Mus., XVI, 1892, 221 (Costa Rica). — Salvin and 

 Godman, Biol. Centr.-Am., Aves, II, 1892, 302 (Costa Rica [fide Gould] 

 Talamanca [Zeledon, in U. S. Nat. Mus.]). 



Saucerottia niveoventer Hartert, Tierr., 1900, 54 (Costa Rica and Panama). — 

 Bangs, Auk, XXIV, 1907, 295 (Boruca [Underwood]). 



Carnegie Museum: Boruca and Buenos Aires de Terraba (Carriker). 



Twenty-three skins. 



This handsome species is confined to the extreme southwestern por- 

 tion of Costa Rica, in other words the Terraba Valley, and is even 

 rare in the upper part of that region. It is very abundant at Boruca, 

 and is evidently common from there southward through the Pacific 

 slope of Chiriqui. They are attracted in great numbers by the flowers 

 of the " Guava " tree, of which there are considerable numbers in the 

 village of Boruca, p'anted there by the Indians years ago. C. F. 

 Underwood collected over one hundred specimens in Boruca in 1906, 

 yet when I was there the following year they were still very common. 

 Where the birds spend the time while the guava trees are not in 

 blossom I do not know, but very likely in the scrub and second- 

 growth so common in that region. 



244. Amizilis tzacatl dubusi (Bourcier and Mulsant). 



Trochilus dubusi Bourcier & Mulsant in Ann. Soc. Agric. Lyon, ser. 2, v. 4, 



141. 

 Amazilia rieferi Cherrie, Expl. Zool. en C. R., 1890-1 (Buenos Aires); Auk, 



IX, 1892, 325 (San Jose, the most abundant species). — Salvin, Cat. Birds 



