Stagnicola emarginata, S. petoskeyensis and S. contracta. Stagnicola emarginata is a common species in northern Michigan and southern Canada but S. petoskeyensis and S. contracta are each known from only one locality. The latter two species are on the state's list of endangered species. Stagnicola petoskeyensis already may be extinct.
John B. Burch (photographer; copyright holder), Mollusk Division, Museum of Zoology, University of Michigan-Ann Arbor