An ostracode fauna of eleven species is described from the Eocene Capay formation at Fig-Tree Gulch, Marysville Buttes, California. One species is considered to be conspecific with a Gulf Coastform, one is described as a nomen apertum, and nine are new. The genera Cytherella, Bythocypris, Buntonia, Paijenborchella, Munseyella, Trachyleberis, Trachyleberidea, and Actinocythereis are represented. The most noteworthy generic occurrence is that of Paijenborchella, hitherto unreportedfrom the Western Hemisphere