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Show 280 EOCENE PERIOD· [Ch. XX.. A great number of the marine shells of this clay have been identified with those of the Paris basin, and are mentioned by name in Appendix I. It is quite evident, therefore, that these two formations belong to the same epoch. No remains of terrestrial mammalia have as yet been found in this clay, but the occurrence of bones and skeletons of cr0 • codiles and turtles prove, as Mr. Conybeare justly remarb, the existence of neighbouring dry land. The shores, at least, of some islands were accessible, whither these creatures may have resorted to Jay their eggs. In like manner, we may infer the contiguity of land from the immense number of ligneous seed-vessels of plants, some of them resembling the cocoa·nut, and other spices of tropical regions, which have been found fossil in great profusion in the Isle of Sheppey. Such is the abundance of these fruits, that they have been supposed to belong to several hundred distinct species of plants. Bagshot sand.-The third and uppermost group, usually termed the Bagshot sand, rests conformably upon the London clay, and consists of siliceous sand and sandstone devoid of organic remains, with some thin deposits of marl associated. From these marls a few marine shells have been obtained which are in an imperfect state, but appear to belong to Eocene species common to the Paris basin'~. Fresh-water st-rata of the Hampshi·re basin.-In the northern part of the Isle of Wight, and part of the opposite coast of Hampshire, fresh.water strata occur resting on the London day. They are composed chiefly of calcareous and argillaceous marls, interstratified with some thick beds of siliceous sand, and a few layers of limestone sometimes slightly siliceous. The marls are often green, and bear a considerable resemblance to the green marls of Auvergne and the Paris basin. The shells and gyrogonites also agree specifically with some of those most common in the French deposits. Mr. Webster, who first described the fresh-water formation of Hampshire, divided it into an upper and lower series separated by intervening beds of marine * Warburton, Geol. Trans., vol. i. Second Series, Oh. XX.] MAMMIFEROUS REMAINS-ISLE OF WIGHT. 281 origin. There are undoubtedly certain intercalated strata, both in the Isle of Wight and coast of Hampshire, marked by a slight intermixture of marine and fresh-water shells, sufficient to imply a temporary return of the sea, before and after which the waters of a lake, or rather, perhaps, some large river, prevailed*. The united thickness of the fresh-water and intercalated upper marine beds, exposed in a vertical precipice in Headen Hill, in the Isle of Wight, is about 400 feet, the marine series appearing about half way up in the cliff. Eocene mammiferous remains.-Very perfect remains of tortoises and the teeth of crocodiles have been procured from the fresh-water strata, but a still more interesting discovery has recently been made. The bones of mammalia corresponding to those of the celebrated gypsum of Paris, have been disinterred at Binstead, near Ryde, in the Isle of Wight. In the ancient quarries near this town a limestone, belonging to the lower fresh-water formation, is worked for building. Solid beds alternate with marls, wherein a tooth of an Anoplotherium, and two teeth of the genus Pa1reotherium, were found. These remains were accompanied not only by several other fragments of the bones of Pachydermata (chiefly in a rolled and injured state), but also by the jaw of a new species of Ruminantia, apparently closely allied to the genus Moschus t. Mr. T. Allan of Edinburgh had several years before found the tooth of an Anoplotherium at the same spot, and when we alluded to this in our first volume :j:, we threw out some doubts as to the authenticity of his specimen, stating at the same time, that in the Binstead beds, if anywhere in our island, we should expect such remains to be found. Although we carried our scepticism too far, it has been attended with good results, for it induced Mr. Pratt to visit Binstead, where he verified and extended the discovery of Mr. Allan. • See M~moirs of Mr. Webster, Geol. Trans., vol. ii., First Series, vol. i. part i., Se~ond Series, and Englefield's Isle of Wight.-Professor Sedgwick, Anu, of Phil., 1822, and Lyell, Geol. Trans., vol. ii. Second Series. t Pratt,Proceedings of Geol. Soc., No. 18, p. 239. l First Edition, p. 153. |
