Abstract: Clitocybe (Fr.) Staude subg. Clitocybe sect. Bulluliferae (Sing.) Harmaja (Agaricales) is considered to deviate so much from the rest of the genus Clilocybe that a new genus, Singerella Harmaja, with Agaricus hydrogrammus Fr. as the type, is proposed for this single valid species. of the section. The most important distinguishing character of the section Bulluliferae is the presence of peculiar vesicles in the hyphae of the epicutis (and mostly also in those of the cortex of the stipe), here called »intercalary dermatochrysocystidia», which are lacking in the other species of Clitocybe, and are probably also absent from the remainder of the Agaricales. They somewhat resemble the normal terminal chrysocystidia present in certain dark-spored gooera. The second distinctive character is in the spores, some of which possess confluent bases. The odour of the species is almost unique in Clitocybe. Certain characters not reported before, such as responses to cotton blue of certain parts of the fruit body of the species in question, are given. The synonymy of A. hydrogrammus is given, two new synonyms of the species being included, resulting to the expansion of the area of this species to the southern hemisphere. One new combination becomes necessary: Singerella hydrogramma (Fr.) Harmaja.