| Convoluta convoluta (Abildgaard, 1806) | prior to 1905 | littoral | | |
| Convoluta paradoxa Ørsted, 1843 | prior to 1882 | | | |
| Monochoerus illardatus Lohner & Micoletzky, 1911 | 1911 or earlier | planktonic, pelagic | | open sea plankton in Istrian waters. found by Triest after south storms, but found regularly at Rovigno. |
| Adenopea illardata (Lohner & Micoletzky, 1911) | 1911 or earlier | planktonic, pelagic | | open sea plankton in Istrian waters. found by Triest after south storms, but found regularly at Rovigno. |
| Stenostomum sieboldi Graff, 1878 | Aug 1876 | | | Port of Trieste. Few specimens in the proximity of Leuchtthurmes. On Zostera. |
| Stylochus tardus Graff, 1878 | 1876 or earlier | | | |
| Proxenetes gracilis Graff, 1882 | prior to 1882 | | | lively animal found between aquatic plants in the Bays of Triest and Neapel. |
| Hypotrichina tergestina Calandruccio, 1897 | 1897 or earlier | | | parasite on Nebalia. Notes that species is found in Trieste, Marsiglia, and Napoli. Repiachoff did not name the species. |
| Microstomum papillosum Graff, 1882 | 1913 or earlier | | | Litoral. |
| Trigonostomum setigerum setigerum Schmidt, 1852 | 1913 or earlier | | | |
| Trigonostomum penicillatum (Schmidt, 1857) | 1913 or earlier | | | on Zostera. |
| Monoophorum striatum (Graff, 1878) | 1913 or earlier | 0-28 m | | among Ulven, Bryozoans. |
| Monocelis longiceps (Duges, 1830) | 1913 or earlier | | | |
| Monocelis fuhrmanni Midelburg, 1908 | 1908 or earlier | | | |
| Otocelis rubropunctata (Schmidt, 1852) | 1933 or earlier | | | Zostera. |
| Convoluta hipparchia Pereyaslawzewa, 1892 | 1933 or earlier | | | |
| Leptoplana tremellaris (Müller, 1773) | 1933 or earlier | | | |
| Thysanozoon brocchii (Risso, 1818) | 1933 or earlier | | | |
| Pseudoceros maximus Lang, 1884 | 1933 or earlier | | | Sacchetta; after Micoletzky 1910, floating close to the surface. |
| Plagiostomum siphonophorum (Schmidt, 1852) | 1933 or earlier | | | |
| Polycystis crocea (Fabricius, 1826) | 1933 or earlier | | | |
| Stylochus luteus Graff, 1882 | 1882 or earlier | | | Triest, Messina, Italy. |
| Stylochus sp. Minot, 1877 | 1877 or earlier | | | Triest, Italy. |