The planorbid species that were described by Shuichi (Syuiti) Mori from Japan have long been enigmatic and their taxonomy has been highly confused. This situation is also an impediment to action for the conservation of Japanese planorbids which are one of the most threatened freshwater snail groups in the country. Based on our examination of Shuichi Mori’s collection stored in the Kyoto University Museum, type materials of the taxa described by him are re-illustrated and re-examined for the first time. Our examination suggested that Gyraulus amplificatus (Mori, 1938) is not a morphological form of Gyraulus biwaensis but a distinct species. Gyraulus pulcher (Mori, 1938) can be regarded as a junior synonym of Gyraulus chinensis.

日本的森秀一（Syuiti）森（Syuichi（Syuiti）Mori）所描述的浮游生物长期以来一直是个谜，它们的分类法也引起了极大的困惑。这种情况也阻碍了保护日本浮游动物的行动，而浮游动物是日本最受威胁的淡水蜗牛种群之一。根据对京都大学博物馆中保存的森秀一收藏品的审查，首次对他所描述的分类单元的类型材料进行了重新说明和审查。我们的研究表明，Gyraulus amplificatus（Mori，1938）不是biwaensis的形态学形式，而是一种独特的物种。Gyraulus pulcher（Mori，1938）可以看作是Gyraulus chinensis的初级同义词。