Type material for 373 nominal species of fossil gastropods is in the Invertebrate Paleontology Collections of Yale University's Peabody Museum of Natural History. Primary types for 193 nominal species include 164 holotypes, 191 syntypes (representing 29 nominal species) and 4 lectotypes. Secondary types for 79 nominal species include 228 paratypes (representing 75 nominal species) and 9 paralectotypes (representing 4 nominal species). Tertiary types of 172 nominal species include 1034 hypotypes. Most types are from St. Louis (Missouri), Chazy (New York), Zorritos (Peru) and Syria and have been described by T.D.A. Conrad, J. B. Knight, E.T. Nelson and P.E. Raymond.