Arionoidei
Family: Arionidae
| Scientific Name | Author/s | Common Name | Last Record | Distribution | Status | Taxon Profile |
| Anadenulus cockerelli | (Hemphill, 1890) | American keeled slug | - | California (southern), USA | Rediscovered | Access |
| Arion simrothi | Kunkel, 1909 | ? | Germany | Missing | Access | |
| Arion transsylvanus | Simroth, 1885 | - | - | Poland (east) & Romania | Rediscovered | Access |