SUMMARY
The species of Bourdotia and Basidiodendron known from the U.S.S.R. are described and illustrated. The genus Bourdotia is emended to include B. galzinii and an unnamed species. Bourdotia galzinii is shown to have petiolate basidia and to be cospecific with Sebacina petiolata. Bourdotia galzinii, which seems to be a common species in the Transcaucasia of the U.S.S.R., is widely distributed in western Europe, but the most northern known American collection site is New Orleans, Louisiana. Sebacina cremea is transferred to Basidiodendron, and the second known collection is identified from the Stanovoy Mountains. Basidiodendron cinereum, B. caesiocinereum, and B. eyrei are shown to be widely distributed in the U.S.S.R. and to occur on both coniferous and angiosperm wood. The concept of B. cinereum is redefined to exclude Sebacina stratosa and Basidiodendron rimosum. The available studies indicate that Basidiodendron cinereum and B. eyrei are probably cosmopolitan, whereas B. caesiocinereum is seemingly restricted to the temperate zones of the Northern Hemisphere.