Three families from the class of Gastropoda are commonly found here. Members of the family Planorbidae are found in flattened shells. Those belonging to Lymnaeidae are found in "right-handed" shells, in which the spiral goes clockwise. Members of Physidae are called "left-handed" as the spiral of the shell goes counterclockwise. Common gastropods in streams also include Ancylidae and we find Bithyniidae in Lake Champlain. Remember that gastropods only count if there is an individual in the shell; don't count empty shells in your data!