A female adult European bird differs from the average of North American examples in the conspicuous longitudinal streaks on the jugulum; but in a male these are hardly more distinct than in 13,077, ♀, Liberty Co., Georgia; 11,983, “United States”; 35,456, Peel’s River; 35,449, ♀, and 35,445, ♀, Fort Yukon, Alaska; 35,452, La Pierre’s Hous., H. B. Ter.; 35,459 ♂, Fort Anderson; and 28,099 ♀, Hartford, Conn. In none of these, however, are they so numerous and conspicuous as in a European female from the Schlüter Collection, which, however, differs in these respects only from North American specimens. A somewhat melanistic individual (in second year? 32,735, Chicago, Ill.; Robert Kennicott) differs as follows: Above continuously pure black; upper tail-coverts and longer scapulars bordered terminally with rusty-whitish. Tail distinctly tipped with white; the inner webs of feathers with eight elliptical transverse bars of pale ochraceous, and indications of corresponding spots of the same on outer webs, forming as many inconspicuous bands. Beneath ochraceous-white; the neck, breast, and abdomen thickly marked with broad longitudinal stripes of clear black,—those on the jugulum cuneate, and on the breast and abdomen broadly sagittate; the tibiæ with numerous cordate spots, and sides marked more transversely; lower tail-coverts with narrow distant transverse bars. On the chin and throat only, the whitish is immaculate, on the other portions being somewhat exceeded in amount by the black. Inner web of longest primary with seven transverse elliptical bars of cream-color. Wing, 12.20; tail, 9.40. Whether the North American and European Peregrine Falcons are or are not distinct has been a question undecided up to the present day; almost every ornithologist having his own peculiar views upon the relationship of the different forms which have been from time to time characterized. The most favorably received opinion, however, seems to be that there are two species on the American continent, and that one of these, the northern one, is identical with the European bird. Both these views I hold to be entirely erroneous; for after examining and comparing critically a series of more than one hundred specimens of these birds, from every portion of America (except eastern South America), including nearly all the West India Islands, as well as numbers of localities throughout continental North and South America, I find that, with the exception of the melanistic littoral race of the northwest coast (var. _pealei_), they all fall under one race, which, though itself exceedingly variable, yet possesses characters whereby it may always be distinguished from the Peregrine of all portions of the Old World.