Simple Animals
Cnidaria - includes
- Hydrozoa - as in Hydra and Obelia
- Anthozoa - corals & sea anemones
- Scyphozoa - true jellyfish
Platyhelminthes - includes
- Turbellaria - commensals & free-living representatives, such as Dugesia
- Cestoda - tapeworms
- Digenea - digenetic flukes