text: Scintillons are not identical in different species. Scintillons isolated from dinoflagellates belonging to the genus Pyrocystis such as P. lunula (previously Dissodinium lunula) or P. noctiluca are less dense than those of L. polyedra and do not contain LBP. Little is known about the structure or composition of scintillons in species other than L. polyedra.