A study of the sole original species of Belonidium Mont. & Dur. revealed that this generic name has been misapplied by subsequent authors. The taxon is redefined as a subgenus of Dasyscyphus S. F. Gray. A brief account is given of the latter genus and its subdivisions and of other genera assigned to the Hyaloscyphaceae trib. Lachneae ( Psilachnum Höhn., Diplocarpa Massee) and subfam. Trichocyphelloideae ( Lachnellula P. Karst., Perrotia Boud.) transferred from the Helotiaceae to the Hyaloscyphaceae, as well as of some other genera, Trichodiscus Kirschst., Lasiobelonium (Sacc.) Sacc. and Zoellneria Vel. The taxonomic significance of lanceolate paraphyses, characteristic in the Hyaloscyphaceae of the Lachneae, and in other families of Helotiales is discussed, with notes on Cenangiopsis Rehm, Mollisiopsis Rehm and other genera. The species previously referred to Belonidium by De Notaris and later authors are reviewed and suggestions are made as to their taxonomic positions and status with incidental notes on such genera as Belonopsis (Sacc.) Rehm, Calycellina Höhn., Strossmayeria S. Schulz., Allophylaria Karst., and the introduction of Nipterella Starbäck ex Dennis, gen. nov. Hymenoscyphus S. F. Gray is taken up for the bulk of species currently referred to Helotium Pers. New combinations are made with Allophylaria (1), Belonopsis (2), Calycellina (1), Cenangiopsis (2), Dasyscyphus (12), Hymenoscyphus (3), Lachnellula (17), Lasiobelonium (1), Nipterella (2), Perrotia (3), Pezizella (1), Psilachnum (2), Strossmayeria (1), Unguicularia Höhn. (1).