Land & Freshwater Gastropods

     Although not as well-publicized as their marine gastropod relatives, the shells of certain few snail species inhabiting the land and fresh waters are known to occur in the abnormally-reversed-coiled condition. Actually, the number of species and individual specimens with reversed symmetry appears to be greater among this group (with terrestrial pulmonate shells accounting for the lion's share) than among seashells - rather surprising considering that far fewer species and individuals of nonmarine than of marine shells have come to our attention.

Aquatic Prosobranchs

Aquatic Pulmonate

Terrestrial Prosobranchs

Terrestrial Pulmonates