Cap bell-shaped or ovate at first, then expanded, smooth, obtuse, viscid, margin even, creamy-white, brown, or greenish, without warts; flesh white; stem white, hollow or stuffed, bulbous at the base, annulate; gills rounded and ventricose, coarse, and persistently white, free from the stem; volva conspicuous, large, loose, adhering to the base, but free from the stem at the top, with the margin irregularly notched. In the white forms there is frequently a greenish or yellow tinge at the disk or centre of the cap. The white form is most common, but the brownish is often found in this country. I have not yet found the green-capped variety sometimes figured in European works. In the brown variety the stem and ring are often tinged with brown, as also the volva. The cap is usually from 2 to 3 inches broad, and the stem from 3 to 5 inches long. The whole plant is symmetrical in shape and clean looking, though somewhat clammy to the touch when moist. It is very common in mixed woods, in some localities, and is universally considered as fatally poisonous. The white form of A. _phalloides_, although in reality bearing very little resemblance to the common field mushroom, has been mistaken for it as also for the _Smooth white lepiota_, and in some instances has been eaten with fatal results by those who gathered it. The distinction between this most poisonous Amanita and the common field mushroom is well marked. In the common mushroom the _gills_ are _pink, becoming dark brown_, the _spores purplish brown_, and the whole mushroom is stout and short stemmed, the stem being shorter than the diameter of the cap, and having no volva, or wrapper at its base. In the species A. _phalloides_ the _gills_ are _persistently white_ and the bulb is distinct and broad at the base, the white cup-shaped wrapper sheathing the base of the stem like the calyx of a flower. The _Smooth white lepiota_ shows neither volva nor trace of one, and has other distinct characteristics which distinguish it from A. _phalloides_. See page 14, No. 4 of this series. The specimen figured in Plate XV grew in Maryland, where it is quite common. PLATE XV. FIG. 9.--=Ag. (Amanita) mappa (Amanita mappa)= Linn., =Amanita citrina=, =A. virosa.= POISONOUS. Cap at first convex, then expanded, dry, without a separable cuticle, not warty but showing white, yellowish, or brownish scales or patches on its upper surface; gills white, adnexed; flesh white, sometimes slightly yellowish under the skin; stem stuffed, then hollow, cylindrical, yellowish white, nearly smooth, with a distinctly bulbous base; volva white or brownish. Odor pleasant. Spores spheroidal. The cap in this species is somewhat variable in color, but those having a white cap are most common. The plant is not so tall as those of the species _phalloides_. It is solitary in habit, and is found usually in open woods. Curtis and Lowerby figure _mappa_ and _phalloides_ under the same name.