I. I ntroduction . T he district to which this paper refers extends from Leith Hill in the west to Tilburstow Hill in the east, and the beds more partieularly discussed are those which have been described by the Geological Survey as the Hythe and S~mdgate Beds. I exclude the Atherfield Clay from consideration here because, although rarely exposed in the district, it is so distinct in itself and of such persistent occurrence at the base of the series, that there can be no reason for doubting its position as mapped. Many geologists have treated of this district in the past; amongst the chief are Mantell, Fitton, T. Webster, Murchison, Mr. C. J. A. Meÿer, and Mr. F. Drew with Mr. W. Topley. The Weald Memoir of the Geological Survey prepared by Mr. Topley, so far as this district is concerned, chiefly from the notes of the late Mr. Drew, sets forth what may be called the hitherto accepted view of the Lower Greensand succession. That view is, that the northern outcrop of the series (as here limited) in the Weald is divisible into three sets of beds, named respectively the: Hythe, Sandgate, and Folkestone Beds, which are mapped more or less continuously from the typical areas after which they are named. This view would no doubt have sufficed, but for the new light thrown on the question in 1885 by Dr. G. ,1. Hinde's paper ‘ On Beds of Sponge-remains in the Lower and Upper Greensand of the South of England ‘ It should