SUMMARYThe species ofExidiopsisknown to the authors from the U.S.S.R. are noted. Those species not previously studied in detail are described and illustrated. The genusExidiopsisis emended to exclude the type and closely related species ofEichleriella. Exidiopsis candida, previously known only from tropical and subtropical regions, is shown to occur on Sakhalin Island.Exidiopsis effusa, on angiosperm wood, is reported from eastern Siberia and European U.S.S.R.Exidiopsis grisea, on gymnosperm wood, was identified from several sites in the Transcaucasia. A previously undescribed species,E. gypsea, is shown to occur in the Crimean Peninsula, Transcausasia, and Estonian S.S.R.Exidiopsis calceais reported from throughout the U.S.S.R. and apparently occurs on both angiosperm and gymnosperm wood. It is the most frequently collected and widely distributed species ofExidiopsisin the U.S.S.R. Additional collections ofE. griseobrunneaare noted from Siberia, and a new subspecies,E. griseobrunneasubsp.macrogyna, is described. Both subspecies ofE. griseobrunneaare apparently only able to utilize species ofDuschekiaas a substrate. Additional collections ofE. laccataandE. pallida, which have been previously reported from the U.S.S.R. were not noted.