Rhodacmea
Rhodacmea is a genus of small freshwater snails or limpets, aquatic gastropod mollusks in the family Planorbidae, the ram's horn snails and their allies. "Rhodacmea" is the type genus of the subfamily Rhodacmeinae. Anatomy. These animals have a pallial lung, as do all pulmonate snails, but they also have a false gill or "pseudobranch". This serves as a gill, which is necessary as, in their non-tidal habitat, these limpets never reach the surface for air. Species. Species in the genus "Rhodacmea" include: