Cercariae of Schistosomatium douthitti (Cort, 1914) Price, 1931 have been obtained from 92 of 2474 Lymnaea stagnalis appressa Say and Lymnaea palustris elodes Say collected from nine locations in central and western Ontario from 1957 to 1960. This is believed to be the first published record of the occurrence in Canada of this schistosome dermatitis-producing parasite. A second schistosome, Trichobilharzia ocellata (La Valette, 1855) Brumpt, 1931, was found in Lymnaea stagnalis appressa Say from two locations.