Critical revision of type material of Stemonitales (Myxogastria) at the Natural History Museum London (BM) Author Moreno, G. gabriel.moreno@uah.es Author Castillo, A. gabriel.moreno@uah.es Author Thüs, H. Current Address: State Museum of Natural History Stuttgart, Germany. & The Natural History Museum, London, United Kingdom text Phytotaxa 2018 2018-03-14 344 2 149 159 http://dx.doi.org/10.11646/phytotaxa.344.2.3 journal article 10.11646/phytotaxa.344.2.3 1179-3163 Comatricha longipila Nann. - Bremek., Acta Bot. Neerl. 11: 31 (1962) Type :— NETHERLANDS , Gelderland , developed in moist chamber on bark obtained from a living oak, 7 April 1961 , N.E. Nannenga-Bremekamp , BM 4839 [ BM 001088435 = box, BM 001247192 = slide, BM 001247200 = SEM stub]. Nannenga-Bremekamp (1962: 34) compares Comatricha longipila with C. laxa Rostaf. and C. subcaespitosa Peck. The latter is considered nowadays to be a synonym of Stemonitopsis subcaespitosa (Peck) Nann. -Bremek ( Nannenga-Bremekamp 1991 ). The latter two species have larger spores, an observation which is confirmed by our measurements. A study of the types of these species was carried out by Castillo et al. (1997) and Moreno et al. (2004) respectively. Our images show that Comatricha longipila has a capillitium similar to species of the genus Stemonaria Nann. -Bremek., R . Sharma & Y. Yamam., but the solid instead of a hollow stalk, separate it from species in that genus.