[189-A] See Proceedings of Roy. Soc., No. 44. p. 233. [190-A] Lyell and Murchison, sur les Depots Lacust. Tertiaries du Cantal, &c. Ann. des Sci. Nat. Oct. 1829. CHAPTER XVI. EOCENE FORMATIONS--_continued_. Subdivisions of the Eocene group in the Paris basin--Gypseous series--Extinct quadrupeds--Impulse given to geology by Cuvier's osteological discoveries--Shelly sands called sables moyens--Calcaire grossier--Miliolites--Calcaire siliceux--Lower Eocene in France--Lits coquilliers--Sands and plastic clay--English Eocene strata--Freshwater and fluvio-marine beds--Barton beds--Bagshot and Bracklesham division--Large ophidians and saurians--Lower Eocene and London Clay proper--Fossil plants and shells--Strata of Kyson in Suffolk--Fossil monkey and opossum--Mottled clays and sands below London Clay--Nummulitic formation of Alps and Pyrenees--Its wide geographical extent--Eocene strata in the United States--Section at Claiborne, Alabama--Colossal cetacean--Orbitoid limestone--Burr stone. From what was said in the two preceding chapters, it has already appeared that we have in England no true chronological representative of the Miocene faluns of the Loire, and none of the Upper Eocene group described in the last chapter. But, when we descend to the middle and inferior divisions of the Eocene system of France, we find that they have their equivalents in Great Britain. MIDDLE EOCENE.--FRANCE. _Gypseous series_ (2. _a_, Table, p. 175.).--Next below the upper marine sands of the neighbourhood of Paris, we find a series of white and green marls, with subordinate beds of gypsum. These are most largely developed in the central parts of the Paris basin, and, among other places, in the Hill of Montmartre, where its fossils were first studied by M. Cuvier. The gypsum quarried there for the manufacture of plaster of Paris occurs as a granular crystalline rock, and, together with the associated marls, contains land and fluviatile shells, together with the bones and skeletons of birds and quadrupeds. Several land plants are also met with, among which are fine specimens of the fan palm or palmetto tribe (_Flabellaria_). The remains also of freshwater fish and of crocodiles and other reptiles, occur in the gypsum. The skeletons of mammalia are usually isolated, often entire, the most delicate extremities being preserved; as if the carcasses, clothed with their flesh and skin, had been floated down soon after death, and while they were still swoln by the gases generated by their first decomposition. The few accompanying shells are of those light kinds which frequently float on the surface of rivers, together with wood.