Cheilanthes Eatoni: Root-stock short, chaffy with rather long slenderly acuminate glossy scales; stalks clustered, four to eight inches long, erect, wiry, covered, as are the rachis and its divisions, with narrow shining pale-ferruginous scales and paleaceous hairs intermixed; fronds four to nine inches long, oblong-lanceolate, pubescent above with whitish entangled woolly hairs, beneath covered with a heavy matted ferruginous tomentum, and more or less scaly, especially when young, tripinnate; pinnæ ovate-oblong, lower ones rather distant, upper ones crowded; ultimate pinnules contiguous, half a line long, rounded, but narrowed at the base, the terminal ones often twice larger and more decidedly obovate; margin of the pinnules continuously recurved, the edge slightly membranaceous. _Cheilanthes Eatoni_, Baker, Syn. Fil., p. 140.—Porter & Coulter, Synopsis of the Flora of Colorado, p. 153.—Eaton, Ferns of the South-West, p. 315. _Cheilanthes tomentosa_, Hooker, Sp. Fil., ii., p. 96 (description and Texas plant), t. cix., _A._—Eaton, in Botany of the U. S. and Mexican Boundary Survey, p. 234. Hab.—Texas and New Mexico, Wright, No. 816; Fendler, No. 1016; Indian Territory, between Fort Cobb and Fort Arbuckle, Palmer; near Cañon City, Colorado, Brandegee; from the Rio Grande westward along the Gila to the Colorado River, Collectors of Mexican Boundary Survey. The kind of place where this fern has been collected is not recorded, but it probably grows in the clefts of rocks along the sides and edges of cañons. Description:—This fern bears so close a resemblance to _Cheilanthes tomentosa_, that it is not at all surprising that there has been more or less of confusion between the two. It would seem that when writing his account of the genus _Cheilanthes_ for the Species Filicum, Sir W. J. Hooker had, in his collection, no examples of the North Carolina _C. tomentosa_, and could identify it only by Link’s rather imperfect description and Kunze’s remarks in Silliman’s Journal. Having Wright’s specimens of the plant here described, and Gordon’s fern from the Rattene Mountains—a plant not yet satisfactorily identified—he referred them to the species named by Link; and then perceiving with his accustomed delicate discrimination that Lindheimer’s and Bradbury’s plant was distinct from Wright’s, he gave the former the name of _C. Bradburii_. It was not until 1860, when the Ferns for Chapman’s Flora were being prepared, that any one suspected that the _C. Bradburii_ was the true _C. tomentosa_. In 1866, I had an opportunity of explaining the matter to Mr. Baker, then at work on the Synopsis Filicum, and not long after, I was surprised, and I need not say pleased, by finding that he had given to Hooker’s _C. tomentosa_ the name it now bears.