Introduction.—We are indebted to Mr. Prestwich for a clear conception of the age of the Bracklesham series, and of its place among the Eocene Tertiaries; while the late Mr. Dixon has described the fossils of Bracklesham and Selsea, and given a very interesting account of the coast of that part of Sussex. In the course, however, of collecting specimens from these beds during the last eight years, I have been led to think that there are many points of interest on which a more minute description of the succession of their subordinate divisions, and of the fossiliferous localities, might be acceptable.