Subphylum

Rhabditophora

Parakontikia ventrolineata. Photo: (c) James Bailey, some rights reserved (CC BY-NC)

Rhabditophora (from rhabdito-, rhabdite + Greek -φορος , bearer, i.e., “rhabdite bearers”) is a class of flatworms. It includes all parasitic flatworms (clade Neodermata) and most free-living species that were previously grouped in the now obsolete class Turbellaria. Therefore, it contains the majority of species in the phylum Platyhelminthes, excluding only the catenulids, to which they appear to be the sister group.

— Wikipedia