Tyler S, Rieger R M
Science. 1975 May 16;188(4189):730-2. doi: 10.1126/science.1124394.
An ultrastructural study of Nemertoderma (Turbellaria, Nemertodermatida) has revealed that its spermatozoa have only a single falgellum. This is the first uniflagellate spermatozoon known in the Turbellaria; it is indicative of the primitiveness of Nemertoderma and is evidence in support of the view that the Turbellaria as a whole are among the most primitive living Bilateria.
对纽形涡虫（涡虫纲，纽形涡虫目）的超微结构研究表明，其精子仅有一条鞭毛。这是涡虫纲中已知的首个具单鞭毛的精子；它表明了纽形涡虫的原始性，也为整个涡虫纲是现存最原始的两侧对称动物之一这一观点提供了证据。
