(cat-owe-din-ee-um) common coastal marine dinoflagellate. The cingulum (circumferential groove) is located near the posterior of the body so that the epicone (front part) is much bigger than the epicone (back part). This genus is in part distinguished by the groove near the apex of the epicone. This individual is clearly a carnivore. With longitudinal flagellum trailing behind the cell. Phase contrast.