Xenoturbella is a genus of very simple bilaterians up to a few centimeters long. It contains a small number of marine benthic worm-like species.
Convolutidae is a family of acoels. It contains more than a third of all known acoel species.
Acoela, or the acoels, is an order of small and simple invertebrates in the subphylum Acoelomorpha of phylum Xenacoelomorpha, a deep branching bilaterian group of animals, which resemble flatworms. Historically they were treated as an order of turbellarian flatworms.
Actinoposthiidae is a family of acoels.
Childia is a genus of acoels in the family Mecynostomidae.
Diopisthoporus is a genus of acoels. It is the only genus in the monotypic family Diopisthoporidae
Hallangiidae is a family of Acoela. It contains 2 species in 2 genera.
Mecynostomidae is a family of acoels.
Nemertodermatidae is a family of wormlike animals in the phylum Acoelomorpha. They are similar to the flatworms of the phylum Platyhelminthes, and were traditionally classified as such.
Isodiametridae is a family of acoels.
Centrovarioplana tenuis is a species of Maricola triclad that is found in Antarctica. It is the only species known in the monotypic genus Centrovarioplana and the family Centrovarioplananidae.
Neppia is a genus of dugesiid triclad that is found in South America, Subantarctic region, Africa, Tasmania and New Zealand.
Pseudostomum is a genus of flatworms in the family Pseudostomidae.
Microstomum is a genus of flatworms in the family Microstomidae.
Monocelididae is family of marine turbellarian flatworms in the order Proseriata, sub order Lithophora.
Meara is a genus of bilaterally symmetric, small aquatic worms in the phylum Acoelomorpha. This genus contains only one species, Meara stichopi, a parasite of the sea cucumber Parastichopus tremulus. It occurs in Norway and Sweden.
Multipeniata is a genus of flatworms in the order Prolecithophora. It is the only genus in the monotypic family Multipeniatidae.
Faerlea is a genus of acoels belonging to the family Isodiametridae.
Intoshia is a genus of worms belonging to the family Rhopaluridae.
Nemertoderma is a genus of worms belonging to the family Nemertodermatidae.
