Turbellarians are free living

Turbellaria (L. turbella - a string) is a class of phylum-Platyhelminthes. Turbellarians are mostly free, living flat worms, majorly aquatic (marine), presence of cilia, body unsegmented, mouth ventral, suckers absent with tango, chemo and photoreceptors, eg, Planaria (Dugesia), Bipalium etc. Trematoda (Gr. trema = hole; eidos = form), class of phylum-Platyhelminthes. Commonly called 'flukes', ecto or endoparasites, body without cilia, unsegmented with suckers and hooks, eg, Fasciola, Schistosoma etc.Cestoda (Gr. kestos = girdle eidos = form) is also one of the class of phylum-Platyhelminthes. They are commonly called 'tapeworms' parasites without cilia and sense organs body segmented (pseudometamerism), digestive system absent, eg, Taenia and Echinococcus.