The present communication is divided into four sections—the first giving an account of Iguanodont remains obtained from the Wadhurst Clay near Hastings subsequently to the writer's previous paper on this group; the second devoted to the description of a metatarsus of a Megalosaurian from the same deposits; the third recording some vertebræ of a Sauropterygian from the Purbeck of the Isle of Portland; while the fourth gives a description of an associated series of remains of a Pliosaur from the Oxford Clay near Peterborough. I. The Iguanodonts of the Wadhurst Clay . Two years ago I brought under the ndice of the Society certain remains of large Iguanodonts collected by Mr. C. Dawson, F.G.S., from the Wadhurst Clay (Lower Wealden) in the neighbourhood of Hastings, and now preserved in the British Museum. Among these a left ilium and some associated vertebræ presented such differences from the corresponding bones of Iguanodon Mantelli and I. bernissartensis , that I felt justified in regarding them as the types of a distinct species, for which the name I. Dawsoni was proposed. I was careful at that time to mention that these specimens only were taken as the types, and it is fortunate that this was done, since it now appears that the sacrum and ischium which, in the absence of any evidence to the contrary, were referred lo the same species, belong to a distinct form. Since the publication of that paper Mr. Dawson has assiduously continued his collecting in the quarries of the Wadhurst Clay