Phaeoseptoria eucalypti, with prominent, brown, rough-walled, percurrently proliferating conidiogenous cells, is shown to be distinct from the type species of Phaeoseptoria, P. papayae, which has small, smooth-walled and apparently non-proliferating conidiogenous cells. As no suitable genus exists for P. eucalypti, the new genus Kirramyces is erected for it. Study of various Eucalyptus leaf fungi has shown that the earliest name applied to this fungus is Cercospora epicoccoides, transferred here as Kirramyces epicoccoides. Other synonyms include Hendersonia grandispora and Phaeoseptoria luzonensis. Two other species of Kirramyces, K. eucalypti, based on Cercospora eucalypti, and K. lilianiae n. sp., are recognized. The taxonomic position of Stagonospora delegatensis and of other collections which may represent additional species of Kirramyces requires further investigation. The host ranges of these fungi are discussed in relationship to the subgeneric classification of the genus Eucalyptus.