Todd — New Forms of Finches and Tanagers. 91 



very different, beins much duller, brownish or grayish olive above and dull 

 whitish below, shaded with bufly. The female of true americana is usually 

 rich brown above and strongly buffy below. Wing (type), 61; tail, 50; 

 bill, 11.5; tarsus, 16.5. 



These characters are readily apparent in a series of sixteen specimens 

 from the lower Amazon as compared with another of fifty specimens from 

 French Guiana, the type-locality. 



Type, No. 72,050, Collection Carnegie Museum, adult male; Santarem, 

 Brazil, April 15, 1919; Samuel M. Klages. 



Sporophila castaneiventris rostrata, subsp. nov. 



Similar to Sporophila castaneiventris castaneiventris Cabanis of Guiana, 

 but size averaging slightly larger; bill much heavier (8 mm. long and 7.5 

 mm. deep in type); and chestnut of under parts slightly deeper. 



The much heavier bill of this form is its best character, but the color- 

 difference, although slight, appears to be sufficiently constant in a series of 

 twenty- two specimens to justify its formal separation from the Guiana 

 birds (eleven skins from French Guiana). 



Type, No. 71,511, Collection Carnegie Museum, adult male; Santarem, 

 Brazil, March 26, 1919; Samuel M. Klages. 



Pitylus grossus saturatus, subsp. nov. 



Similar to Pitylus grossus grossus (Linnaeus) of Guiana, Brazil, etc., 

 but males darker, more slaty blue, in general coloration, and females almost 

 uniform dark olive gray below, with little or no buffy brown shade. 



Although Mr. Ridgway (Bull. U. S. Nat. Mus., No. 50, 1, 1901, 652) 

 confesses his inability to distinguish specimens from different parts of the 

 range of this widely distributed species, I find that with an excellent series 

 of birds from the type-locality (French Guiana) before me for comparison 

 the birds from Costa Rica and Colombia can be told at a glance by their 

 darker coloration. Males are darker, more slaty blue, but it is in the 

 females that the difference is most pronounced. Guiana females are 

 strongly shaded below (especially posteriorly) with buffy brown, while 

 Costa Rica females are almost uniform dark olive gray below. Colombian 

 birds are easily referable to this dark form. I select as type an adult 

 female. 



Type, No. 23,493, Collection Carnegie Museum, adult female; Guacimo, 

 Costa Rica, September 25, 1903; M. A. Carriker, Jr. 



Tangara boliviana lateralis, subsp. nov. 



Differs from Tangara boliviana boliviana (Bonaparte) of Bolivia, Peru, 

 etc., in the following respects: the yellow of the under parts, although 

 varying somewhat, is appreciably paler; the blue tips of the feathers on the 

 sides and flanks are shorter, allowing the black subterminal spots to show 

 more (these parts, therefore, appear to be more heavily spotted) ; the blue 

 margins to the middle wing-coverts are narrower; and the lesser wing- 

 coverts usually have a touch of greenish. 



These characters are obvious in the series examined, and would seem to 

 suffice to distinguish the bird of the lower Amazon from that of Bolivia. 



