Laevapex fuscus, dorsal view. This is a common pond species in North America. Notice the tentacles emerging from under the edge of the shell. The red structure showing through the shell between the tentacles is the buccal mass, including the radula, a ribbon of tiny teeth used in feeding. The dark tan mass showing through the center of the shell is the digestive gland.
John B. Burch (photographer; copyright holder), Mollusk Division, Museum of Zoology, University of Michigan-Ann Arbor