| Opistomum pallidum Schmidt, 1848 | 1913 or earlier |  |  | lakes and puddles. | 
| Dalyellia euchroa Gieysztor, 1926 | 1926 or earlier |  |  | near Warsaw. | 
| Catenula sekerai de Beauchamp, 1919 | 1926 or earlier |  |  | near Warsaw. | 
| Dalyellia expedita Hofsten N, 1907 | 1926 or earlier |  |  | near Warsaw. | 
| Dalyellia rubra (Fuhrmann, 1894) | 1926 or earlier |  |  | near Warsaw. | 
| Dalyellia brevimana Beklemischev, 1921 | 1926 or earlier |  |  | near Warsaw. | 
| Dalyellia karisalmica Nasonov, 1917 | 1926 or earlier |  |  | near Warsaw. | 
| Gyratrix hermaphroditus coeca Graff, 1882 | 1926 or earlier |  |  | near Warsaw. | 
| Macrostomum appendiculatum Fabricius, 1826 | 1926 or earlier |  |  | near Warsaw.  Winter eggs. | 
| Phaenocora unipunctata (Ørsted, 1843) | 1926 or earlier |  |  | near Warsaw.  thin-shelled eggs. | 
| Dalyellia penicilla (Braun, 1885) | 1926 or earlier |  |  | near Warsaw.  Two forms, large and small found. | 
| Macrostomum hystrix Ørsted, 1843 | 1891 or earlier |  |  | near Warsaw. | 
| Vortex pictus Schmidt, 1848 | 1891 or earlier |  |  | near Warsaw. | 
| Vortex sexdentatus Graff L, 1882 | 1891 or earlier |  |  | near Warsaw. | 
| Vortex truncatus (Abildgaard, 1789) | 1891 or earlier |  |  | near Warsaw. | 
| Opistomum pallidum Schmidt, 1848 | 1891 or earlier |  |  | near Warsaw. | 
| Microstomum lineare (Müller, 1773) | 1891 or earlier |  |  | near Warsaw. | 
| Microstomum lineare (Müller, 1773) | 1891 or earlier |  |  | near Warsaw. | 
| Gieysztoria sibirica (Plotnikow, 1905) | 1929 or earlier |  |  | Polen.  Warschau, Mai (Gieysztor 1929) | 
| Opistomum pallidum Schmidt, 1848 | 1939 or earlier |  |  | Polen:  Warschau | 
| Castrada (Castradella) granea Braun, 1885 | 1929 or earlier |  |  |  | 
| Strongylostoma radiatum (Müller, 1774) | 1939 or earlier |  |  |  | 
| Strongylostoma elongatum elongatum Hofsten N, 1907 | 1924 or earlier |  |  |  | 
| Rhynchomesostoma rostratum (Müller, 1774) | 1939 or earlier |  |  |  | 
| Olisthanella truncula (Schmidt, 1858) | 1926 or earlier |  |  |  | 
| Mesostoma productum (Schmidt, 1848) | 1939 or earlier |  |  |  | 
| Mesostoma craci Schmidt, 1858 | 1926 or earlier |  |  |  | 
| Mesostoma craci Schmidt, 1858 | 1939 or earlier |  |  |  | 
| Mesostoma rhynchotum Braun, 1885 | 1926 or earlier |  |  |  | 
| Phaenocora typhlops (Vejdovsky, 1880) | 1926 or earlier |  |  |  | 
| Phaenocora unipunctata (Ørsted, 1843) | 1926 or earlier |  |  |  | 
| Macrostomum tuba Graff, 1882 | 1931 or earlier |  |  | Warschau, in Aquarien | 
| Microdalyellia armigera (Schmidt, 1862) | 1939 or earlier |  |  |  | 
| Microdalyellia fairchildi (Graff, 1911) | 1939 or earlier |  |  | Warschau, künstlicher Teich | 
| Microdalyellia brevimana (Beklemischev, 1921) | 1932 or earlier |  |  |  | 
| Microdalyellia picta (Schmidt, 1848) | 1939 or earlier |  |  |  | 
| Microdalyellia rossi (Graff, 1911) | 1939 or earlier |  |  |  | 
| Microdalyellia nanella (Beklemischev, 1921) | 1939 or earlier |  |  | Wigry u. Warschau, austrocknende Kleingewässer | 
| Dalyellia penicilla diminuta Gieysztor, 1929 | 1939 and earlier |  |  |  | 
| Dalyellia scoparia (Schmidt, 1858) | 1926 or earlier |  |  |  | 
| Gieysztoria cuspidata (Schmidt, 1861) | 1926 or earlier |  |  |  | 
| Gieysztoria rubra (Fuhrmann, 1894) | 1939 or earlier |  |  | Warschau. | 
| Gieysztoria euchroa (Gieysztor, 1926) | 1939 or earlier |  |  | Wigry u. Warschau | 
| Castrella (Castrella) truncata (Abildgaard, 1789) | 1926 or earlier |  |  |  |