Collections made during the last twenty years from silty clays of the uppermost Ypresian in La Tuilerie outcrop of Gan enhance our knowledge of the Cypraeidae and Ovulidae of the early Eocene. Within this corpus four new species of Ovulidae are described and one new subgenus (Grovesia n. subgen.) of Ovulidae is introduced. The genera Prionovolva Iredale, 1930 and Sphaerocypraea Schilder, 1927 are herein redefined, the genera Habuprionovolva Azuma, 1970, Simnia Risso, 1826 and Xandarovula Cate, 1973 are discussed, and the genus Sandalia Cate, 1973 is ratified and confirmed in the early Eocene. With 21 species (17 genera and subgenera) the fossil assemblage from the Béarn Basin (Pyrénées-Atlantiques, southwest France) appears to be the most diversified record of Paleogene Cypraeoidea.
Mollusca, Cypraeoidea, Ovulidae, early Eocene, Gan, France, palaeobiodiversity, new subgenus, new species