Gelasinospora is a genus closely related to Sordaria, characterized by the foveolate sculpturing of the spore wall. At present it contains two species, as follows:—I. Gelasinospora tetrasperma, a coprophilous fungus which has been cultivated from spores collected in Manitoba and in Ontario.The species is described, together with illustrations of the chief characters, such as the four-spored condition of the ascus and the thickened ring bordering its apical perforation.Each normal-sized spore gives rise to a homothallic mycelium. The normal spore contains four nuclei. Asci very occasionally produce dwarf spores. Each dwarf spore gives rise to a mycelium which produces archicarps, but no perithecia. The mycelia from dwarf spores fall into two groups, (+) and (−), in regard to their sexual behavior. When (+) and (−) mycelia are paired, perithecia are produced. Sometimes asci contain giant spores. The giant spores usually produce homothallic mycelia and the spores usually contain six nuclei.II. Gelasinospora cerealis, isolated from the crown of wheat and oats in Manitoba.The species is described, together with illustrations of the chief characters, such as the eight-spored condition of the ascus and the two radial thickenings at its apical perforation.Each spore gives rise to a homothallic mycelium. The spores are binucleate.