Helisoma is a genus of freshwater air-breathing snail, a pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. Synonym: Carinifex Binney, 1864 Helisoma snails are an intermediate host of Megalodiscus temperatus. Species Species within the genus Helisoma include: Helisoma anceps, sometimes known as Planorbella anceps Helisoma campanulatum (Say, 1821) : synonym of Planorbella campanulata (Say, 1821) References Planorbidae