The relationships between the Tremellales and Aphyllophorales are discussed by comparison of the micromorphology of some species belonging to the following pairs of genera: Exidiopsis—Athelopsis, Basidiodendron— Dendrothele—Heterochaete, Myxarium—Oliveonia—Repetobasidium, Tremellodendropsis—Aphelaria, Uthatobasidium—Bolryobasidium. A new combination is proposed in the genus Athelopsis.