I. DACTYLYNE, A REVISED STRUCTURE, AND ISODACTYLYNE, A NOVEL HALOGENATED ACETYLENIC COMPOUND. II. THREE NEW SESQUITERPENES FROM THE SEA HARE APLYSIA DACTYLOMELA (RANG): DACTYLENOL, DACTYLENOL ACETATE, AND DACTYLOL. III. ISOLATION OF DENDROLASIN FROM THE SPONGE OLIGOCERAS HEMORRHAGES. IV. ISOLATION OF TWO KNOWN SAPOGENINS FROM THE SEA CUCUMBER HOLOTHURIA ATRA. V. A NOVEL POLACETYLATED COMPOUND FROM A SOFT CORAL. VI. CEMBRENE-A AND TWO NEW CEMBRENE DERIVATIVES.