Abstract: A new genus, Gelatoporia Niemelä, is described, to embrace resupinate polypores with a monomitic structure, clamped hyphae and white-rot. G. pannocincta (Rom.) Niemelä, n. comb., is redescribed. G. subvermispora (Pilát) Niemelä, n. comb. (type of the genus), is reported as new to Fennoscandia. Tyromyces canadensis Overh. ex Lowe (Antrodiella overholtsii Ryv. & Gilb.) is reported for the first time outside North America; its characteristics, taxonomy and nomenclature are discussed. Skeletocutis carneogrisea David is reported as new to Finland and provided with some ecological notes. Skeletocutis odora (Sacc.) Ginns is shown to be an older name for S. tschulymica (Pilát) Keller, Antrodia pulvinasccns (Pilát) Niemelä, n. comb., for A. plicata Niemelä, and A. macra (Sommerf.) Niemelä, n. comb., for Trametes salicina Bres. (Antrodia salicina). Most species are illustrated by photographs and microscopic drawings. A new method of mdicating microchemica reactions is proposed and the reliability of Cresyl Blue in the polypore taxonomy is reviewed.