The species-richness seen in the living molluscan fauna of the East Coast of the United States is due to its composite nature, containing faunal elements from three contiguous molluscan provinces. These include: the southern warm waterCarolinian Molluscan Province (Cape Hatteras, North Carolina to Palm Beach, Florida); the central temperate waterVirginian Molluscan Province (Cape Cod, Massachusetts to Cape Hatteras, North Carolina); and the northern cold waterAcadian Molluscan Province (Labrador, Canada to Cape Cod, Massachusetts). Each of these provinces has been found to house a large component of endemic species, many illustrated for the first time in this book. To place the modern East Coast molluscan fauna within a geochronological perspective, we also give detailed descriptions of the predecessor faunas that are contained in the Miocene, Pliocene, and Pleistocene fossil beds of eastern North America. For the first time in any book on American shells, hundreds of extinct species from these Neogene fossil beds are illustrated in separate chapters, describing the marine ecosystems and molluscan faunas that lived during these times. The living and fossil molluscan faunas from the entire coast, altogether, are illustrated on 128 plates, showing some of the most interesting and beautiful shells that ever evolved anywhere in the world's oceans.