A method of determination of seston in sea water / Shoji Iizuka. Records of maximum occurrence of phytoplankton in various localities / Shoji Iizuka. Feeding habits of planktonic copepods / Masateru Anraku. Suggestion for improvement of gear of plankton sampling, based on experience obtained on the cruise of the 'Koyo Maru' in the Indian Ocean, 1962-1963 / Takuo Chiba.