Additions to the Late Paleocene molluscan fauna from the Santa Monica Mountains, Los Angeles County, southern California

Several previously unreported shallow-marine, warm-water gastropods and bivalves from the upper part of the Santa Susana Formation, east-central Santa Monica Mountains, Los Angeles County, southern California, are described and discussed. The gastropods are Diodora sp. nov.? (Fissurellidae) and Terebralia susana sp. nov. (Potamididae). The bivalves are Solena (Eosolen) stantoni (Weaver, 1905) (Solenidae), Martesia sp. (Pholadidae), and Nototeredo(?) sp. (Teredinidae). These mollusks are of late Paleocene (Thanetian Stage) age. For the Pacific Coast of North America, the specimens of Diodora and Martesia represent the earliest records, the specimens of Terebralia the first confirmed record, and the specimens of Nototeredo(?) the first record. The specimens of Solena (Eosolen) stantoni are the best preserved and largest of this species.