Abstract
Several Japanese investigators have described of the cystophorous cercaria from snails, Semisulcospira spp. in Japan, and its first description was made by Osafune (1899), who recovered it in Okayama Prefecture. Seno (1903), Miyagawa (1913) and Ando (1915, 1918) have also made its descriptions later respectively, but these were very incomplete. Following these reports, Yoshida (1917) made a more detailed description of this cercaria which is called “Cercaria F” by him, obtained in various areas in Japan, and Cort and Nichols (1920) named it Cercaria yoshidae. During the past few years the author have recovered many Semisulcospira spp, in various areas in Japan, some of which are from the same spots where Yoshida has collected it before. These snails are parasitized with some 18 species of trematode larvae, one of which being a cystophorous cercaria presented here. In the following chapter, its morphology, geographical accounts and seasonal distributions in detail are reported.
