The plants of this genus are tough and pliant, becoming hard when old, unless very watery, and when dry. The genus differs from the other tough and pliant ones by the peculiarity of the gills, the gills being notched or serrate on the edges. Sometimes this appearance is intensified by the cracking of the gills in age or in drying. The nearest ally of the genus is _Panus_, which is only separated from _Lentinus_ by the edge of the gills being plane. This does not seem a very good character on which to separate the species of the two genera, since it is often difficult to tell whether the gills are naturally serrate or whether they have become so by certain tensions which exist on the lamellæ during the expansion and drying of the pileus. Schroeter unites _Panus_ with _Lentinus_ (Cohn's Krypt. Flora, Schlesien, =3=, 1; 554, 1889). The plants are usually very irregular and many of them shelving, only a few grow upright and have regular caps. =Lentinus vulpinus= Fr.--This is a large and handsome species, having a wide distribution in Europe and in this country, but it does not seem to be common. It grows on trunks, logs, stumps, etc., in the woods. It was quite abundant during late summer and in the autumn on fallen logs, in a woods near Ithaca. The =caps= are shelving, closely overlapping in shingled fashion (imbricated), and joined at the narrowed base. The surface is convex, and the margin is strongly incurved, so that each of the individual caps is shell-shaped (conchate). The surface of the pileus is coarsely hairy or hispid, the surface becoming more rough with age. Many coarse hairs unite to form coarse tufts which are stouter and nearly erect toward the base of the cap, and give the surface a tuberculate appearance. Toward the margin of the cap these coarse hairs are arranged in nearly parallel lines, making rows or ridges, which are very rough. The hairs and tubercles are dark in color, being nearly black toward the base, especially in old plants, and sometimes pale or of a smoky hue, especially in young plants. The pileus is flesh color when young, becoming darker when old, and the flesh is quite thin, whitish toward the gills and darker toward the surface. The =gills= are broad, nearly white, flesh color near the base, coarsely serrate, becoming cracked in age and in drying, narrowed toward the base of the pileus, not forked, crowded, 4--6 mm. broad. The cap and gills are tough even when fresh. The plant has an intensely pungent taste. Figures 131, 132 represent an upper, front, and under view of the pilei (No. 3315, C. U. herbarium). [Illustration: PLATE 42, FIGURE 131.--Lentinus vulpinus. The coarse, hairy scales are black in old plants, paler, of a smoky hue, in younger ones (natural size). Copyright.]