Very few observations have been made on the Chromatology of the Actiniœ, the reason probably being that observers have been led to believe that since their colouring matters cannot be got into solution with the ordinary solvents, the study of their spectra could hardly be attended with fruitful results. Krukenberg,* who has added much to our knowledge of animal Chromatology generally, has attempted to enlarge the knowledge of this subject by his study of the pigments of Anthea viridis and A. cereus .