Class Turbellaria: Are mostly flatworms. They are bilaterally symetrical animals, in other words their left and right sides are mirror images of each other; this also implies that they have distinct top and bottom surfaces and distinct head and tail ends. Like other bilsterians they are triploblastic having three main cell layers.
Land planarian: A land planarian is a flat worm that lives in the soil and eats vegetation and earthworms. They can get fairly large, up to about a foot.
Dugesia tigrina: Dugesia tigrina is a free-living flatworm found across North America. These flatworms are predators that will eat whatever they can catch. This usually includes small crustaceans, insect larvae
Class Bivalvia: This class contains all the mollusks, including the mussels, oysters, scallops, and clams and worms. All have shells composed of two pieces known as valves. In most, the valves are of similar size, but in some sedentary species, such as the oysters, the upper valve, which covers the left side of the body, is larger than the lower valve
Nemertea (ribbon worms): Typically marine, benthic animals, nemerteans may be found burrowed in mud, sand, or other sediments. Nemerteans are hunters and scavengers.
Entoprocta (hairy back worms): Colonial entoprocts are found living on rocks, shells, algae, and underwater structures, They eat phytoplankton, as well as diatoms and algae.
Class Cestoda: The best-known species are commonly called tapeworms. Cestodes are all parasitic and their life histories vary, but typically they live in the digestive tracts of vertebraes as adults, and often in the bodies of other species of animals as juveniles.
Himantura chaophraya (Freshwater whipray): This species is typically found over sandy bottoms in large rivers, at depths of 5 to 20 meters. Their diet consists mainly of benthic fishes and invertebrates.