Notes on the Histology of Ovarian Eggs of the Epipelagic Octopus Ocythoe tuberculata Caught off Naoetsu Port, Niigata Prefecture, Sea of Japan — Studies on Gonad Maturity in Some Marine Invertebrates－XIII - Honma, Y.; Ushiki, T.; Takeda, M.; Nakamura, Y. (Venus (Journal of the Malacological Society of Japan), 2007)