Land and fresh-water shells of North America. Part III. Ampullariidae, Valvatidae, Viviparidae, fresh-water Rissoidae, Cyclophoridae, Truncatellidae, fresh-water Neritidae, Helicinidae.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith