This is a reprint of Snyder's 2003 publication which is fully updated and includes many additions that did not appear in the earlier work. The book includes a record of all names assigned to shells in this family in the Recent and Fossil Faunas along with their taxonomic placement. The arrangement is alphabetical by the species name with listings of other references used for the species below the main listing. The book is not illustrated but is an excellent source for information about the widely variable mollusks in this diverse family. The last part of this catalog is a bibliography which contains information about every reference source that the author used to compile this important research tool.