1. Y. Kakinuma, Bull. Mar. Biol. Stat., Asamushi, Tohoku Univ.,10, 37 (1960);
2. M. Nishihira, Bull. Mar. Biol. Stat., Asamushi, Tohoku Univ.,13, 83 (1968), and13, 91 (1968). References on the biological properties of several kinds of hydrozoa are cited therein.
3. Ph. D. thesis of A. S.Kumanireng, Tohoku University (1973).
4. Details of the syntheses will be described elsewhere.
5. Acknowledgment. We are indebted to Hoffman-La Roche for the financial support, and thanks are due to Mr. Y.Kato of Hitachi Co, Ltd., for his measurement of high resolution mass spectra.