| Stenostomum grande Child, 1902 | 1923 or earlier | | | |
| Stenostomum unicolor Schmidt, 1848 | 1923 or earlier | | | |
| Stenostomum leucops (Duges, 1828) | 1923 or earlier | | | |
| Rhynchoscolex simplex Leidy, 1852 | 1923 or earlier | | | |
| Macrostomum appendiculatum Fabricius, 1826 | 1923 or earlier | | | |
| Syndesmis echinorum Francois, 1886 | 1913 or earlier | | | in sea urchins [Strongylocentrotus droebachensis (Müll.), S. lividus Brdt., Sphaerechinus granularis A.Ag., Echinus sphaera Müll., E. acutus Lam.] |
| Castrada (Castrada) inermis Hofsten N, 1911 | 1925 or earlier | | | pools and moorland ditches of high moutain locations (altitudes 1780-2400 m). |
| Castrada (Castrada) instructa Hofsten N, 1907 | 1925 or earlier | | | |
| Castrada (Castrada) stagnorum Luther, 1904 | 1925 or earlier | | | |
| Castrada (Castrada) hofmanni Braun, 1885 | 1925 or earlier | | | |
| Castrada (Castrada) viridis Volz, 1898 | 1925 or earlier | | | |
| Castrada (Castrada) intermedia (Volz, 1898) | 1925 or earlier | | | |
| Castrada (Castrada) armata (Fuhrmann, 1894) | 1925 or earlier | | | |
| Castrada (Castrada) neocomensis Volz, 1898 | 1925 or earlier | | | |
| Castrada (Castrada) luteola Hofsten N, 1907 | 1925 or earlier | | | |
| Mesostoma lingua (Abildgaard, 1789) | 1925 or earlier | | | |
| Polycystis crocea (Fabricius, 1826) | 1913 or earlier | | | |
| Pseudostomum quadrioculatum (Leuckart, 1847) | 1913 or earlier | | | |
| Dalyellia ornata Hofsten N, 1907 | 1932 or earlier | | | |
| Dalyellia infundibuliformis (Fuhrmann, 1894) | 1932 or earlier | | | |
| Dalyellia armigera Schmidt, 1861 | 1932 or earlier | | | |
| Castrella (Castrella) truncata (Abildgaard, 1789) | 1932 or earlier | | | lake. |
| Opistomum tundrae Nasonov, 1923 | 1924 or earlier | | | |
| Olisthanella arctica Nasonov, 1923 | 1924 or earlier | | | |
| Olisthanella septentrionalis Nasonov, 1924 | 1924 or earlier | | | |
| Strongylostoma radiatum (Müller, 1774) | 1932 or earlier | | | |
| Strongylostoma elongatum Hofsten N, 1907 | 1932 or earlier | | | |
| Rhynchomesostoma rostratum (Müller, 1774) | 1932 or earlier | | | |
| Tetracelis marmorosa (Müller, 1773) | 1932 or earlier | | | |
| Castrada (Castrada) stagnorum stagnorum Luther, 1904 | 1932 or earlier | | | |
| Castrada (Castrada) sphagnetorum Luther, 1904 | 1932 or earlier | | | |
| Castrada (Castrada) libidinosa Hofsten, 1916 | 1932 or earlier | | | |
| Mesostoma lingua (Abildgaard, 1789) | 1932 or earlier | | | |
| Mesostoma murmanicum Nasonov, 1923 | 1932 or earlier | | | |
| Polycystis goettei Bresslau, 1906 | 1932 or earlier | | | |
| Gyratrix hermaphroditus hermaphroditus Ehrenberg, 1831 | 1932 or earlier | | | moss, leafs. |
| Prorhynchus stagnalis Schultze, 1851 | 1932 or earlier | | | damp earth, moss. |
| Geocentrophora baltica (Kennel, 1883) | 1932 or earlier | | | damp earth, moss. |
| Geocentrophora sphyrocephala de Man, 1876 | 1932 or earlier | | | |
| Bothrioplana semperi Braun, 1881 | 1932 or earlier | | | |
| Syndesmis echinorum Francois, 1886 | 1903 or earlier | | | intestine of Strongylocentrotus dröbachiensis (O.F. Müller) at Alexandrowsk (von Graff, 1903 |
| Microdalyellia armigera (Schmidt, 1862) | 1924 or earlier | | | Halbinsel Kola, Alexandrovsk |
| Mesostoma lingua (Abildgaard, 1789) | 1923 or earlier | | | |
| Microdalyellia armigera (Schmidt, 1862) | 1924 or earlier | | | |
| Microdalyellia arctica (Nasonov, 1923) | 1923 or earlier | | | in fliessendem Wasser von 10-11º C bei der Biologischen Station Alexandrovsk. |
| Microdalyellia brevispina (Hofsten, 1911) | 1925 or earlier | | | Tundren |
| Gieysztoria ornata (Hofsten N, 1907) | 1923 or earlier | | | Halbinsel Kola, Alexandrovsk |
| Castrella (Nasonoviella) lutheri (Nasonov, 1917) | 1925 or earlier | | | Alexandrovsk, >>überall verbreitet in den Gewässern der Tundra>> |