SUMMARYFour different staining procedures were performed on 35 species and four varieties in the following genera of rhodophylloid fungi:Leptonia, Nolanea, Entoloma, Alboleptonia, Rhodocybe, andClaudopus.Six features were correlated with existing generic and subgeneric taxa. Histochemically,Leptoniais distinguished by the presence of granules and dark staining cells in the pileipellis. The subgenusLeptoniapossesses only dark staining cells, whereas the subgenusPaludocybepossesses both dark staining cells and“granules.”Alboleptoniais distinguished by a distinctively colored suprapellis.Rhodocybeis distinguished due to a green sublayering effect in the pileipellis andClaudopusby unique color reactions of the suprapellis in three of the four staining procedures employed. Species ofNolaneapossess a distinctive coloration of the subpellis (pileipellis) while other reactions are absent.Entolomais distinguished by homogeneous coloration throughout the pileipellis. Based upon the specific reactions with the stains in each of the genera, different macrochemical as well as microchemical tests to define the genera are suggested.