=R. oliva´cea= Fr.—_oliva_, an olive; _olivaceus_, the color of an olive. =Pileus= 2–4 in. across, dingy-purple then olivaceous or wholly brownish-olivaceous, fleshy, convexo-flattened and depressed, _slightly silky and squamulose_, margin spreading, even. =Flesh= _white, becoming somewhat yellow_. =Stem= firm, ventricose, rose-color to pallid, spongy-stuffed within. =Gills= adnexed, wide, _yellow_, with shorter and forked ones intermixed. Mild. Near to R. rubra, but certainly distinct in the stem being definitely spongy, in the pileus being unpolished, and in the gills being soft and brightly colored; corresponding with R. alutacea. _Fries._ =Spores= light yellow, _Fries_; spheroid, punctate, 10µ _Q._; globose, minutely granulate, yellow, 9–10µ diameter _Massee_. Mt. Gretna, Pa., 1897–1898. =Pileus= 2–4 in. across, 2–3 in. long, ½-⅓ in. thick. The caps are equally good with R. alutacea. They must be fresh, and similarly cooked. =R. fla´vida= Frost—yellow. (Plate XLIV, fig. 3, p. 184.) =Pileus= fleshy, convex, slightly depressed, unpolished, bright yellow. =Gills= white, adnate, turning cinereous. =Stem= yellow, solid, white at the extreme apex. _Frost_ Ms. =Pileus= fleshy, convex, slightly depressed in the center, not polished, yellow, the margin at first even, then slightly striate-tuberculate. =Gills= nearly entire, venose-connected, white, then cinereous or yellowish. =Stem= firm, solid, yellow, sometimes white at the top. =Spores= yellow, subglobose, 6.5–7.6µ in diameter. =Flesh= white, taste mild. =Plant= 2–3 in. high. =Pileus= 2–3 in. broad. =Stem= 4–6 lines thick. _Frost_ Mss. Ground in woods. Sandlake. August. _Peck_, 32d Rep. N.Y. State Bot. R. flavida is showy, solitary and in patches. The stem when young and solid is equally good with the cap. Cooks in twenty-five minutes and is of good flavor. HETEROPHYL´LÆ. =R. ves´ca= Fr.—_vesco_, to feed. =Pileus= _red-flesh-color, disk darker_, fleshy, slightly firm, plano-depressed, _slightly wrinkled with veins_, with a viscid pellicle, margin at length spreading. =Flesh= cheesy, firm, shining white. =Stem= _solid_, compact, externally rigid, _reticulated and wrinkled_ in a peculiar manner, often attenuated at the base, shining white. =Gills= adnate, crowded, thin, shining white, with many unequal and forked ones intermixed, but scarcely connected by veins. Of middle stature. _Taste mild_, pleasant. _Fries._ =Spores= globose, echinulate, white, 9–10µ diameter. _Massee_. In mixed woods. Common. August to frost. R. vesca is frequent in woods or margins, and under trees in the open. It is especially fond of growing in the grass under lone chestnut trees. The caps seldom exceed 2-½ in. across. It is one of the best.