In the eocene, miocene, and pliocene tertiary deposits, I know only of two species of Scalpellum, and two of Pollicipes, with indications of two or three other species, all distinct / from recent forms. It is a rather singular fact, considering the present wide distribution of the genus Lepas or Anatifa, and the frequency of the individuals, that not a single valve known certainly6 to belong to this genus, or to any of the closely allied genera, has hitherto been found fossil.