Keys to and critical notes on the European species of the genera Marasmiellus and Rhodocybe are given. The nomenclature of Macrocystidia is elucidated. Two rare species, viz. Rhodocybe melleopallens and R. fallax are fully described and illustrated. Rhodocybe mundula is reduced to the synonymy of R. popinalis. Rhodocybe nauceodulcis is transferred to Omphaliaster. The new combinations Rhodocybe microsporum (Velen.) Noordel., Marasmiellus omphaliformis (Kühn.) Noordel., Omphaliaster nauseodulcis (Horak) Noordel. and O. kyrtosporus (Horak) Noordel. are made.