One-hundred and sixteen genera are listed as incertae sedis in the class Dothideomycetes. This is a first of a series of papers in which we re-examine the herbarium types of these genera, which are generally poorly known. By examining the generic types we can suggest higher level placements, but more importantly we illustrate the taxa so that they are better understood. In this way the taxa can be recollected, sequenced and placed in a natural taxonomic framework in the Ascomycota. In this study we re-examined the genera Dermatodothella, Dothideopsella, Gloeodiscus, Grandigallia and Hysteropeltella. We re-describe and illustrate the type species of these genera and discuss their placements using modern concepts. Dermatodothella is placed in Polystomellaceae, Dothideopsella in Phaeosphaeriaceae, Grandigallia in Shiraiaceae and Hysteropeltella in Schizothyriaceae, while Gloeodiscus is retained in Dothideomycetes incertae sedis. Fresh collections of these genera are needed for further studies, so that they can be epitypified and molecular data can be analyzed to obtain a natural classification.