Intralichen gen. nov. is introduced for four dematiaceous hyphomycetes with mycelia growing inside the hymenia and thalline tissues of lichens or lichenicolous fungi and sporulating at the surface: L baccisporus sp. nov., I. christiansenii comb. nov. (syn. Bispora christiansenii), L lichenicola comb. nov. (syn. Trimmatostroma lichenicola), and L lichenum comb. nov. (syn. B. lichenum). A key to the species is provided and all known hosts and reports of the species are summarized.