Stagnicola elodes, Michigan. This is a common freshwater pulmonate snail of the northern United States and southern Canada. Notice the fleshy mantle collar bordering the shell aperture. This is the past of the mantle that secretes the shell. Just inside the angle of the mantle collar can be seen the closed pneumostome.
John B. Burch (photographer; copyright holder), Mollusk Division, Museum of Zoology, University of Michigan-Ann Arbor