| Nominal Species (n = 7) | Present allocation (n = 6) | Ref. |
|---|---|---|
| Oceania armata Kolliker, 1853 | Oceania armata | 19 |
| Rhizogeton conicum Schuchert, 1996 | Rhizogeton conicum | 8278 |
| Rhizogeton ezoense Yamada, 1964 | Rhizogeton ezoense | 8278 |
| Rhizogeton fusiformis Agassiz, 1862 | Rhizogeton fusiformis | 19 |
| Rhizogeton nematophorum Antsulevich, 1986 | Similomerona nematophora | 1663 |
| Rhizogeton nudum Broch, 1910 | Rhizogeton nudum | 1663 |
| Oceania tydemani Bleeker & van der Spoel, 1988 | Oceania armata | 8278 |