In August 1965, a scallop dredge from R/V Albatross brought up many pieces of fossiliferous opaline chert or porcellanite of Eocene age from Fippennies Ledge, a bank 70 m deep in the central Gulf of Maine. Their presence in this area supports the idea that part of the Gulf is underlain by sedimentary rocks of Tertiary age. Occurrence in the porcellanite of two identifiable species of Bryozoa (ascophoran Cheilostomata), Kleidionella lobata Canu and Bassler and "Ocheto-sella" robusta Canu and Bassler, suggests (1) correlation with the Castle Hayne Limestone of Claiborne to Jackson age; (2) a temperate zone, distinctly American biogeographic provenance; and (3) accumulation in quiet water.