| Polycelis felina (Dalyell, 1814) | 1958 or earlier | | | .... scarce in the Western Islands and the north of Scotland and it may be excluded from harsher habitats as a result of competition for food with P. nigra... |
| Crenobia alpina (Dana, 1766) | 1981 or earlier | | | In Britain ...commonly found under stones and among vegetation, characteristically in spring heads and small, cool, swift streams. |
| Dendrocoelum lacteum (Müller, 1773) | 1981 or earlier | | | Throughout Britain this species is common, especially in productive lakes. It has not spread to the north of Scotland or the Western Islands and its distribution is closely linked to that of Asellus (Isopoda), which affords it a 'food refuge' |
| Bipalium kewense Moseley, 1878 | 1981 or earlier | | | it is generally associated with exotic plants of greenhouses |
| Rhynchodemus sylvaticus (Leidy, 1852) | 1944 or earlier | | | first recorded from Britain by Pantin (1944) |
| Microplana terrestris (Müller, 1773) | 1944 and earlier | | | It is widely distributed in Britain and Ireland under logs, stones, decaying wood, etc. lying in dark shady places |