The =pileus= is fleshy, soft, flexible, convex, to expanded, or obconic, plane or depressed, or funnel-shaped, the margin strongly inrolled when young, in age simply incurved, the margin plane or repand and undulate. The color varies from ochre yellow to dull orange, or orange ochraceous, raw sienna, and tawny, in different specimens. It is often brownish at the center. The surface of the pileus is minutely tomentose with silky hairs, especially toward the center, and sometimes smooth toward the margin. The flesh is 3--5 mm. at the center, and thin toward the margin. The gills are arcuate, decurrent, thin, the edge blunt, but not so much so as in a number of other species, crowded, regularly forked several times, at length ascending when the pileus is elevated at the margin. The color of the =gills= is orange to cadmium orange, or sometimes paler, cadmium yellow or deep chrome. The =stem= is clay color to ochre yellow, enlarged below, spongy, stuffed, fistulose, soft, fibrous, more or less ascending at the base. The taste is somewhat nutty, sometimes bitterish. The plants in Fig. 127 (No. 3272, C. U. herbarium) were collected near Ithaca, October 7, 1899. MARASMIUS Fr. In this genus the plants are tough and fleshy or membranaceous, leathery and dry. They do not easily decay, but shrivel up in dry weather, and revive in wet weather, or when placed in water. This is an important character in distinguishing the genus. It is closely related to _Collybia_, from which it is difficult to separate certain species. On the other hand, it is closely related to _Lentinus_ and _Panus_, both of which are tough and pliant. In _Marasmius_, however, the substance of the pileus is separate from that of the stem, while in _Lentinus_ and _Panus_ it is continuous, a character rather difficult for the beginner to understand. The species of _Marasmius_, however, are generally much smaller than those of _Lentinus_ and _Panus_, especially those which grow on wood. The stem in _Marasmius_ is in nearly all species central, while in _Lentinus_ and _Panus_ it is generally more or less eccentric. Many of the species of the genus _Marasmius_ have an odor of garlic when fresh. Besides the fairy ring (_M. oreades_) which grows on the ground, _M. rotula_ is a very common species on wood and leaves. It has a slender, black, shining stem, and a brownish pileus usually with a black spot in the depression in the center. The species are very numerous. Peck, 23rd Report, N. Y. State Mus., p. 124--126, describes 8 species. Morgan Jour. Cinn. Soc. Nat. Hist. =6=: 189--194, describes 17 species.