=O. umbellif´era=—_umbella_, a little shade; _fero_, to bear. From its umbrella-like shape. (Plate XXXIV, p. 132.) =Pileus= about ½ in. broad, commonly whitish, _slightly fleshy-membranaceous_, convex then plane, _broadly obconic_ with the decurrent gills, not at all or only slightly umbilicate, hygrophanous, when moist watery, _rayed with darker striæ_, when dry even, changeable in appearance, silky, flocculose, rarely squamulose, _the margin, which is at first inflexed, crenate_ (scalloped). =Stem= _short_, not exceeding 1 in. long, almost 1 line thick, stuffed then soon tubed, slightly firm, equal or dilated toward the apex into the pileus, of the same color as the pileus, commonly _smooth_, but varying pubescent, white villous at the base. =Gills= _very broad behind, triangular_, decurrent, _very distant_, edge of the gills straight. Cosmopolitan. The common form is to be found everywhere from the sea level to 4,000 feet. _Stevenson._ =Spores= 3×4µ _W.G.S._; 10×4µ _W.P._; green variety 10×6µ _W.P._; broadly elliptical, 8–10×5–6µ _Peck_. O. umbellifera is known the world over. It is very variable in size and color. With us it is seldom over ¾ in. broad. =Stem= ½-1 line thick. It grows on decaying wood and ground full of decaying material. There are several varieties. All are edible, but not worth describing. This description is given that the student may recognize one of our common plants, and eat it, if very hungry. MYCENA´RII. =O. campanel´la= Batsch.—_campana_, a bell. =Pileus= thin, rather tough, hemispherical or convex, glabrous, umbilicate, hygrophanous, rusty yellow-color and striatulate when moist, paler when dry. =Gills= moderately close, arcuate, decurrent, yellowish, the interspaces venose. =Stem= firm, rigid, hollow, _brown_, often paler at the top, _tawny-strigose at the base_. =Spores= elliptical, 6–7×3–4µ. =Pileus= 4–8 lines broad. Stem about 1 in. long, scarcely 1 line thick. Much decayed wood of coniferous trees. Very common. May to November. _Peck_, 45th Rep. N.Y. State Bot. =Spores= ellipsoid, 6–8×3–4µ _C.B.P._; 7×3µ _W.P._; 6–9×3–4µ _B._ The quantity alone, in which this small species can be found, makes it worth mentioning as an edible species. It is common over the United States where coniferous trees abound. Its favorite habitat is upon the rotting debris of these trees. Occasionally it grows from the ground, but only from that which is heavily charged with woody material. It is social in troops, or affectionate in clusters, or maintains a single existence. It is edible, of good substance when stewed, tender and of fair flavor. [Illustration: Photographed by Dr. J.R. Weist. PLATE XXXV. PLEUROTUS OSTREATUS. ] PLEURO´TUS. _Gr._—a side; _Gr._—an ear. =Stem= excentric, lateral or none. _Epiphytal_ (_very rarely growing on the ground_), irregular, fleshy or membranaceous. _Fries._