Pond snails (various): Freshwater, algae-eating snails.
Ramshorn snails: Herbivorous, freshwater snails with beautiful spiral-shaped shells.
Live, active (relatively) snails for the classroom. Representing the phylum Mollusca and demonstrating key characteristics of the group - a muscular foot, and a mantle-secreted shell. Snails are shipped moist in shallow “bait” containers. Sold by the dozen.