Three new species of Podocopid Ostracoda (Families Cytheruridae and Pontocyprididae) are described from washings of Riftia pachytila tubes and associated sediment at the Tica and Riftia hydrothermal vent fields at 9°50'N on the East Pacific Rise: Xylocythere vanharteni n. sp., Thomontocypris brightae n. sp., and Thomontocypris gollnerae n. sp.