DROPLETS FROM THE PLANKTON NET XXI. WHITE SHELLS OF IANTHINA PROLONGATA BLAINVILLE1)

The fishermen of this vicinity were annoyed by the drop in price of mackerel and jack mackerel caught so richly in the coastal waters of this area after the end of August. Probably this was caused by the disappearance of the cooler coastal water mass and the approach of the warm water current toward shore. On Sunday afternoon, September 5, 1965, at the end of his summer vacation my son, Takasi, Jr., found a number of pleustonic animals were just being stranded on the northern sand beach of the laboratory. Being helped by the small boy, Chihiro NISHIMURA, he gathered most of them and brought the collection to me for observation. This collection included 643 janthinas, 62 portuguese-men-of-war, 3 velellas and a considerable number of porpitas. The last members were less than 38 mm in diameter and mostly heavily damaged. Vel ella was less than 23 mm in length and the sail was stretched from the left above to right below (NW to SE). Of 62 physalias 56 were right-handed individuals, while the other 6 were left-handed and very small, less than 19 mm in length of pneumatophore