Family Campanulinidae Hincks, 1868

Colony stolonal or erect, hydrocaulus branched or unbranched; hydrotheca usually campanulate or cylindrical, with or without pedicel, always with operculum of several triangular flaps; sharply demarcated from hydrotheca or not; with or without diaphragm; with or without nematophores; gonophores as fixed sporosacs or free medusae.