The fronds vary from a few inches to over a foot in length; their general shape is ovate-lanceolate, or oblong-lanceolate; they are in general of a grayish color from the abundance of a fine entangled tomentum, which covers both surfaces, though it is a little thinner and whiter on the upper surface. The large fronds are fully tripinnate. The primary pinnæ are oblong-ovate, short-stalked, one to nearly two inches long, and a half to three-fourths of an inch broad at the base. They are either opposite or alternate, the lower ones, as usual, more separated than those that are higher up on the frond. The secondary pinnæ are close-placed, oblong, obtuse, and again pinnated into from two to five minute rounded or rounded-obovate sessile or adnate-decurrent pinnules on each side, besides a terminal oval pinnule which is twice as large as the lateral ones. These ultimate pinnules are innumerable, and it is in allusion to their very great number in this and the allied species that the generic name _Myriopteris_ was proposed by Fée for the group. The whole margin of the pinnule is recurved, and from the edge of it is produced a very delicate whitish involucre, the whole forming a sort of pouch, as is admirably represented in the figure given by Fée. The sporangia have a ring of about twenty articulations: Fée says there are vittate or knotted hairs growing among them. The spores are rather large, amber-colored, globose, and delicately trivittate. According to Fée, when placed in water they burst and dissolve into excessively minute sporules. There can be no doubt that our plant is the _Cheilanthes tomentosa_ of Link. Kunze, who knew Link’s plant perfectly well, referred the North Carolina specimens to it; and Dr. Mettenius, who succeeded to the care of the Leipzig garden, favored me with specimens which are precisely the same thing as the plant here described. But none of the Mexican collectors seem to have found the species, and it may be legitimately queried whether the commonly reported origin of Link’s specimens is the true one. The _Cheilanthes tomentosa_ of the _Species Filicum_ is partly this plant, but mainly the species next to be described. CHEILANTHES EATONI, Baker. Eaton’s Lip-Fern.