The =pileus= is convex, then expanded, plane or convex, and when mature more or less top-shaped because it is so thick at the middle. In age the surface of the cap often becomes cracked into small areas, showing the yellow flesh in the cracks. The flesh is yellowish and the surface is dry. The =gills= are not very distant, they are stout, chrome yellow to lemon yellow, and strongly decurrent. A few of them are forked toward the base, and the surface and the space between them are marked by anastomosing veins forming a reticulum suggestive of the hymenium of the _Polyporaceæ_. This character is not evident without the use of a hand lens. The surface of the gills as well as the edges is provided with clavate =cystidia= which are filled with a yellow pigment, giving to the gills the bright yellow color so characteristic. These cystidia extend above the basidia, and the ends are rounded so that sometimes they appear capitate. The yellow color is not confined to the cystidia, for the sub-hymenium is also colored in a similar way. The =spores= are yellowish, oblong to elliptical or spindle-shaped, and measure 8--12 × 3--5 µ. The =stem= is the same color as the pileus, but paler, and more yellow at the base. It is marked with numerous minute dots of a darker color than the ground color, formed of numerous small erect tufts of mycelium. Figure 160 is from plants (No. 3977 C. U. herbarium) collected at Blowing Rock, N. C., during September, 1899. As stated above, the plant was first described by de Schweinitz as _Agaricus rhodoxanthus_ in 1822. In 1834 (Synop. fung. Am. Bor. p. 151, 1834) he listed it under the genus _Gomphus_ Fries (Syst. Mycolog. 319, 1821). Since Fries changed _Gomphus_ to _Gomphidius_ (Epicrisis, 319, 1836--1838) the species has usually been written _Gomphidius rhodoxanthus_ Schweinitz. The species lacks one very important characteristic of the genus _Gomphidius_, namely, the slimy veil which envelops the entire plant. Its relationship seems rather to be with the genus _Paxillus_, though the gills do not readily separate from the pileus, one of the characters ascribed to this genus, and possessed by certain species of _Gomphidius_ in even a better degree. (In Paxillus involutus the gills do not separate so readily as they do in certain species of _Gomphidius_.) Berkeley (Decades N. A. Fungi, 116) has described a plant from Ohio under the name _Paxillus flavidus_. It has been suggested by some (see Peck, 29th Report, p. 36; Lloyd, Mycolog. Notes, where he writes it as _Flammula rhodoxanthus_!) that _Paxillus flavidus_ Berk., is identical with _Agaricus rhodoxanthus_ Schw.