During the summer of 1967 one of us (Mazzer) collected parasitized specimens of a rhodophylloid agaric in which the gills were aborted and the pilei were covered with perithecia. Subsequent study of the parasite indicated that it was an undescribed species of Hypomyces. Also in 1967 when Tylopilus rubrobrunneus Mazzer & A. H. Smith (Mich. Bot. 6: 58-59. 1967) was described, aborted (parasitized) carpophores were illustrated (Mich. Bot. 6: 64, 65, figs. 14, 15. 1967). These aborted specimens were suggestive of specimens of an aborted bolete bearing perithecia collected near Ann Arbor by Paul Marchand in 1961. Study of this material revelaed that it too was an undescribed species of Hypomyces.