free-living flatworms

Turbellaria are a group of generally small (<1 - 60cm) and free-living members of the flatworm phylum Platyhelminthes. It is nowadays mostly considered obsolete (polyphyletic), and the Acoela and Nemertodermata are excluded from the class into a phylum of their own (Acoelomorpha).

An extensive group of worms which have the body covered externally with vibrating cilia. It includes the Rhabdocœla and Dendrocœla. Formerly, the nemerteans were also included in this group.