Bangs — Rare or Not Well Known Costa Rira.n Birds. 37 



Euphonia gnatho (Cabanis). 



After very careful study of all available material I am convinced that all 

 Costa Rican birds (some of which have been called Euphonia hirundi- 

 nacea Bonap. ) are in reality referable to Euphonia gnatho, and that that 

 species is an excellent one. I am glad to be able to state that Ridgway 

 now thoroughly agrees to this. 



The bill, though it varies much individually in size, is always larger, 

 sometimes very much larger in E. gnatho than in E. hirxindinacea and 

 always different in shape. The female is much yellower below than the 

 female of E. hirundinacea, though this varies individually somewhat, the 

 extreme being reached in the female described by Ridgway* from Pigres. 

 The male is always metallic greenish-blue above, in place of the metallic 

 dark blue of E. hirundinacea, the difference being very striking on com- 

 parison of series. 



Though E. gnatho does not appear to be a very connnon species, I now 

 have a fairly large series, including both sexes, from various parts of Costa 

 Rica, and from the Caril)bean as well as the Pacific areas. 



Phoenicothraupis alfaroana Ridg. 



On Tenorio and in the Cerro 8ta. Maria this recently described ant 

 tanager was quite abundant, and a series of tifty-four specimens was taken 

 in January and February, 1908. Considerable individual variation in ))oth 

 sexes is presented by this series, and many skins are much darker in color 

 than any among the original specimens from Miravalles. Some examples, 

 in fact, come very close to P. rubica nelsoni of Yucatan, and I am rather 

 inclined to the belief that the form is really the palest race of rubica, and 

 its relationship to P. rubra of South America is more distant. 



Chlorothraupis carmioli (Lawr. ). 



At LaVijagua in Fel)ruary, 1908, Underwood found Carmiol's tanager 

 in large numbers and took upwards of sixty specimens. Some dozen indi- 

 viduals in this series are extensively, but irregularly, marked about the 

 head, throat, scapulars and sides of the breast with dull vermilion, and 

 others are slightly so marked. The red markings are not due to extra- 

 neous staining, but to red pigment in the feather itself. Both sexes show 

 this red mottling and I am unable to account for it unless it be reversion 

 to some ancestral bright-colored bird, like Piranga, which the irregular 

 nature of the markings rather suggest. 



Aimophila rufescens hypaethrus subsp. nov. 



Type from Cerro Sta. Maria, northern Costa Rica. No. 21,606, collection 

 of E. A. and O. Bangs, c? adult, collected January 4, 1908, by C. F. 

 Underwood. 



Characters. — A well-marked geographic race, nearest to Aimophila 

 rufescens rufescens Swains, of southern Mexico and Guatemala, but 

 rather smaller, with the bill actually larger; whole upperparts distinctly 

 darker; lateral crown stripes much more dusky; dusky shaft stripes on 



• Proc. Biol. Soc. Wash., Vol. XVIII, Oct. 17, 1905, pp. 225-22G. 



