Marstonia ogmorhaphe, common names the royal marstonia or royal springsnail, is a minute species of freshwater snail, an aquatic gastropod mollusk or micromollusk in the family Hydrobiidae, the mud snails. This species is endemic to Tennessee in the United States, where it occurs in two streams in Marion County. It is a federally listed endangered species of the United States. This species is threatened by the degradation of water quality in its habitat, which is caused by coal mining and other processes.