Fungal strains in the culture collection of the CBS under the generic names Arachniotus and Pseudoarachniotus were studied. The genera Arachniotus (including Pseudoarachniotus) with 6 species, Narasimhella with a single species, and Amauroascus with 7 species are accepted. For Arachniotus glomeratus, Arachniotus striatisporus and Arachniotus lectardii the new generic names Arachnotheca, Byssoascus, and Eleutherascus are proposed. A key is given for the genera of the Gymnoascaceae.