This is an objective index to the literature, alphabetically listing figured specimens of California pelecypods, gastropods, and scaphopods from Paleocene to Pliocene (up to but not including Lomita ■correlatives).An effort has been made to keep insertions and interpretations clearly separated from authors' statements; information not given in original publications but available through research is bracketed. All stated localities have been checked against maps in an attempt to construe sections, townships, and ranges as well as formations; omissions of locality information have been supplied wherever possible from labels and field notebooks. The formula for each entry in the catalogue is: name combination as cited by the author; author's name; date; reference; author's statement of formation; interpretation; author's statement of age (in quotation marks if there is disagreement); locality, including number, verbal description, construed location, quadrangle, county; cross references and remarks; present repository of figured material, with catalogue number and notes on status of specimens. A species index enables students to trace the various generic allocations made by authors. Concepts adopted herein as to the age-range of cited formations are embodied in a chart.The list is divided into three sections: Pelecypoda, comprising 232 genera and 817 species; Scaphopoda, 2 genera and 14 species; and Gastropoda, 308 genera and 906 species. Approximately half these species occur in Eocene formations. Genera with the greatest number of species are Pecten, Turritella, Cancellaria, and Tellina. ARRANGEM ENTThe three principal classes of Mollusca--Pelecypoda, Scaphopoda, and Gastro poda-are listed separately. Entries are arranged first alphabetically, then chrono logically. Each entry carries the following information, in the order given: generic and specific name, author, date; bibliographic reference in condensed form; forma tion and age; exact locality; remarks; repository. CON VEN TION S EMPLOYED Quotation marks.-Throughout this list double quotation marks are used to indi cate an exact transcription which is here considered erroneous or doubtful. Single quotation marks indicate the use of quotation marks in the original.Brackets.-Material interpolated by the compilers is set apart in square brackets.Many locality descriptions, for example, have been expanded by study of museum labels and other unpublished data. All these and all comments and corrections of errors are clearly set off from the remainder of the list. Material not in brackets is intended to be an exact transcript of the literature. In the notations as to catalogue numbers and status of specimens, however, this rule does not apply, as no attempt has been made to separate published information from that supplied by actual check ing of specimens in type collections. For the accuracy or inaccuracy of statements on repository and catalogue numbers, the compilers must assume full responsibility. Format.-In this quotation of a sample entry, footnotes to the co...