_Gr._—belonging to an umbilicus. (Plate XXXIV.) [Illustration: OMPHALIA UMBELLIFERA. Enlarged about two sizes. ] =Pileus= generally _thin_, usually umbilicate at first, then funnel-shaped, often hygrophanous, margin incurved or straight. =Gills= _truly decurrent_ from the first, sometimes branched. =Stem= distinctly cartilaginous, polished, tubular, often stuffed when young. =Flesh= continuous with that of the pileus but differing in character. =Spores= white, somewhat elliptical, smooth. Generally on wood, preferring hilly woods and a damp climate. Resembling Collybia and Mycena in the flesh of stem and pileus being different in texture and in the externally cartilaginous stem. It is perfectly separated by the gills being markedly decurrent from the first. The American species of Omphalia number between thirty-five and forty. Many of them are common. Few woods are free from them. Several of them are beautiful. They are usually small and lacking in substance. Raw, the writer has not found one that is objectionable in any way; a few have a woody taste. But two species have been found by him in sufficient quantity to make a dish. It is probable that all are edible. At best the species of Omphalia are valuable in emergency only. ANALYSIS OF TRIBES. COLLYBARII. * Pileus dilated from the first, margin incurved. MYCENARII. Pileus campanulate at first, margin straight and pressed to the stem. COLLYBA´RII. * _Pileus dilated from the first; margin incurved._ =O. onis´cus= Fr. _Gr._—a wood-louse. From the ashy color. =Pileus= scarcely 1 in. broad, dark _ashy_ becoming pale, gray-hoary when dry, somewhat membranaceous, or slightly fleshy, _flaccid_, fragile when old, _convexo-umbilicate_ or funnel-shaped, often irregular, undulato-flexuous, even-lobed, _smooth, even_, margin striate. =Stem= 1 in. long, 1 line and more thick, stuffed then tubed, _slightly firm_, moderately tough, sometimes round, curved, sometimes unequal, compressed, ascending, undulated, _gray_. Gills shortly _decurrent_, somewhat distant, quaternate, _ash-color_. Not cespitose. _Fries._ =Spores= 12×7–8µ _B._ Massachusetts, _Sprague_; California, _H. and M._, who record it as edible.