Campanulariidae is a family of animals in the phylum Cnidaria, or stinging-celled animals. Campanulariidae is composed entirely of hydroids, a Greek term meaning "water animals" applied to the plant-like polyp colonies of the class Hydrozoa. All species of the Campanulariidae are aquatic in habitat, primarily inhabiting coastal regions and tidal pools. The genus Laomedea includes such species as and Laomedea flexuosa, which are similar in appearance to the Obelia, though they are smaller and lack a medusa stage present in Obelia.