Critical revision of type material of Stemonitales (Myxogastria) at the Natural History Museum London (BM)

For the first time both Light- and Scanning Electron Microscopy are aplied to re-assess diagnostic characters of type specimens for selected Stemonitales kept in the collections of the Natural History Museum London (BM). The results are used to revise published data and the type status is discussed for specimens of Amaurochaete comata G. Lister & Brândză, Comatricha longipila Nann.-Bremek., Comatricha lurida Lister, Comatricha pulchella (C. Bab.) Rostaf., Comatricha suksdorfii Ellis & Everh., Paradiacheopsis rigida (Brândză) Nann.-Bremek., Stemonaria irregularis (Rex) Nann.-Bremek., R. Sharma & Y. Yamam. and Stemonitopsis microspora (Lister) Nann.-Bremek at BM. A lectotype is proposed for Paradiacheopsis rigida (Brândză) Nann.-Bremek.