Prostoma is a genus of freshwater nemerteans, containing the following species: * Montgomery, 1896 * Gibson & Moore, 1978 * Senz, 1996 * Prostoma eilhardi (Montgomery, 1894) * Prostoma graecense (Böhmig, 1892) * Tarman, 1961 * Prostoma jenningsi Gibson & Young, 1971 * Gibson & Moore, 1976 * Chernyshev et al., 1998 * Beauchamp, 1932