| Prorhynchus stagnalis Schultze, 1851 | 1913 or earlier |  |  |  | 
| Castrella (Castrella) truncata (Abildgaard, 1789) | 1913 or earlier |  |  | ubiquitous, very active, prefers swimming at the surface of cold and warm, standing and flowing water. | 
| Mesostoma lingua (Abildgaard, 1789) | 1913 or earlier |  |  | mud and detritus, of pools, ponds and lakes. | 
| Mesostoma tetragonum (Müller, 1774) | 1913 or earlier |  |  |  | 
| Artioposthia triangulata (Dendy, 1895) | 1988 or earlier |  |  | North Ireland, Scotland and England, U.K. | 
| Artioposthia triangulata (Dendy, 1895) | 1981 or earlier |  |  | Scotland and England, U.K. | 
| Phaenocora unipunctata (Ørsted, 1843) | 1913 or earlier |  |  |  | 
| Dugesia polychroa (Schmidt, 1861) | 1981 or earlier |  |  | fairly widespread, occurring in England, Scotland and Wales. | 
| Planaria torva (Müller, 1773) | 1981 or earlier |  |  | found in England, Scotland and Ireland.  ....its distribution is markedly discontinuous, there being real concentrations in the Edinburgh and Glasgow areas and in East Anglica. | 
| Australopacifica atrata (Steel, 1897) | 2019 or earlier |  |  | ....."Black terrestrial planarians, 5 mm to 3 cm long, have been found in five locations in the United Kingdom, the earliest in 2015. " | 
| Artioposthia exulans (Dendy, 1901) | 2013 |  |  |  | 
| Bipalium kewense Moseley, 1878 | 2021 or earlier |  |  |  | 
| Caenoplana coerulea Moseley, 1877 | 2021 or earlier |  |  |  | 
| Caenoplana variegata (Fletcher & Hamilton, 1888) | 2008 |  |  |  | 
| Arthurdendyus triangulatus (Dendy, 1895) |  |  |  |  | 
| Dolichoplana striata Moseley, 1877 |  |  |  |  | 
| Platydemus manokwari Beauchamp, 1962 |  |  |  |  |