This is now admitted by all pteridologists to be a distinct species; though it was formerly confounded with the _Camptosorus_, from which it is clearly distinguished by the free veins, the mostly single indusia, and the usual absence of a proliferous bud at the apex of the frond. Some of the less compound and more attenuated forms of _A. montanum_ come much nearer to it; but in its simplest form this other species always has the fronds fairly pinnate, and its more compound forms resemble the _A. pinnatifidum_ very little. I take occasion to express my thanks to Hon. Thomas M. Peters of Moulton, Alabama, who has sent me abundant and fine specimens of this fern and of other rare species which are found in the northern part of Alabama. SENSITIVE FERN. [Illustration: ] ONOCLEA SENSIBILIS, Linnæus. Sensitive Fern. Onoclea sensibilis:—Root-stock creeping, elongated; stalks scattered, nearly chaffless, a few inches to over a foot high; fronds dimorphous; sterile ones triangular-ovate, foliaceous, smooth, quickly withering when plucked, deeply pinnatifid into several oblong-lanceolate entire or sinuate or sinuately pinnatifid segments, the lowest pair sometimes distinct, the rest connected by a wing which widens upwards; the veins reticulated and forming narrow paracostal areoles, and, outside of these, copious oblong or hexagonal meshes; fertile fronds shorter, contracted, rigid, closely bipinnate; the pinnules rolled up into berry-like bodies; veins free, simple or forked, soriferous on the back; sporangia borne on an elevated receptacle, half surrounded by a very delicate somewhat hood-like indusium attached at the base of the receptacle. _Onoclea sensibilis_, Linnæus, Sp. Pl., p. 1517.—Michaux, Fl. Bor.-Am., ii., p. 272.—Swartz, Syn. Fil., p. 110.—Schkuhr, Krypt. Gew., p. 95, t. 102.—Willdenow, Sp. Pl., v., p. 287.—Pursh, Fl. Am. Sept., ii., p. 665.—Hooker, Gen. Fil., t. lxxxii; Fl. Bor.-Am., ii., p. 262; Sp. Fil., iii., p. 160.—Torrey, Fl. New York, ii., p. 499.—Gray, Manual, ed. i., p. 457; ed. ii., p. 599, t. xii; ed. v., p. 668, t. xviii; Botany of Japan, in Mem. Amer. Acad. (n. s.) vi., p. 421.—Mettenius, Fil. Hort. Lips., p. 97.—Maximowicz, Prim. Fl. Amur., p. 337.—Eaton, in Chapman’s Flora, p. 596.—Hooker & Baker, Syn. Fil., p. 46.—Miquel, Prolus. Fl. Jap., in Ann. Mus. Bot. Lugd.-Batav., iii., p. 179.—Milde, Fil. Eur. et Atlant., p. 157.—Redfield, in Bulletin of Torrey Botan. Club, vi., p. 4.—Williamson, Ferns of Kentucky, p. 109, t. xli; Fern-Etchings, t. xlv. _Onoclea obtusilobata_, Schkuhr, Krypt. Gew., p. 95, t. 103.—Pursh, Fl. Am. Sept., ii., p. 665. _Onoclea obtusiloba_, Link, Fil. Hort. Lips., p. 37.