| Dalyellia triquetra orientalis Nasonov, 1929 | | w | latest taxonomic authority | |
| Tetracelis viridata Tu, 1939 | | w | latest taxonomic authority | |
| Stenostomum agile japonicum Okugawa, 1930 | | w | primary taxonomic authority (describer) | |
| Dalyellia biwae Okugawa, 1930 | | w | primary taxonomic authority (describer) | 80 |
| Dalyellia gracilis Okugawa, 1930 | | w | primary taxonomic authority (describer) | 81 |
| Dalyellia inflata Okugawa, 1930 | | w | primary taxonomic authority (describer) | 81 |
| Dalyellia japonica Okugawa, 1930 | | w | primary taxonomic authority (describer) | 82 |
| Gieysztoria inflata (Okugawa, 1930) | [with synonyms] | w | primary taxonomic authority (describer) | |
| Gieysztoria japonica (Okugawa, 1930) | [with synonyms] | w | primary taxonomic authority (describer) | 82 |
| Microdalyellia biwae (Okugawa, 1930) | [with synonyms] | w | primary taxonomic authority (describer) | |
| Microdalyellia inflata (Okugawa, 1930) | | w | primary taxonomic authority (describer) | |
| Microdalyellia japonica (Okugawa, 1930) | | w | primary taxonomic authority (describer) | |
| Macrostomum gigas Okugawa, 1930 | | w | primary taxonomic authority (describer) | |
| Macrostomum japonicum Okugawa, 1930 | | w | primary taxonomic authority (describer) | 79 |
| Macrostomum kawamurai Okugawa, 1930 | | w | primary taxonomic authority (describer) | 78 |
| Macrostomum tuba gigas Okugawa, 1930 | | w | primary taxonomic authority (describer) | 77 |
| Gieysztoria (Marcusiella) okugawai (Ruebush & Hayes, 1939) | [with synonyms] | w | other taxonomic work | |