find the remains of these animals, which seem to have been preceded by the _Coryphodon_, and afterwards by the _Lophiodon_; the order of succession in the appearance of these animals is now perfectly established. It may be added that round Paris the Eocene formation, from its lowest beds to the highest, is composed of beds of plastic clay, of the _Calcaire grossier_ with its _Nummulites_, _Miliolites_, and _Alveolites_, followed by the gypseous formation; the series terminating in the Fontainebleau Sandstone, remarkable for its thickness and also for its fine scenery, as well as for its usefulness in furnishing paving-stone for the capital. In Provence the same series of rocks are continued, and attain an enormous thickness. This upper part of the Eocene deposit is entirely of lacustrine formation. Grignon has procured from a single spot, where they were embedded in a calcareous sand, no less than 400 fossils, chiefly formed of comminuted shells, in which, however, were well-preserved species both of marine, terrestrial, and fresh-water shells. Of the Paris basin, Sir Charles Lyell says: “Nothing is more striking in this assemblage of fossil testacea than the great proportion of species referable to the genus _Cerithium_. There occur no less than 137 species of this genus in the Paris basin, and almost all of them in the _Calcaire grossier_. Most of the living _Cerithia_ (Figs. 157 and 168) inhabit the sea near the mouths of rivers, where the waters are brackish; so that their abundance in the marine strata now under consideration is in harmony with the hypothesis that the Paris basin formed a gulf into which several rivers flowed.”[88] [88] “Elements of Geology,” p. 300. To give the reader some idea of the formation, first come the limestones and lower marls, which contain fine lignite or wood-coal produced from vegetable matter buried in moist earth, and excluded from all access of air, a material which is worked in some parts of the south of France as actively as a coal-mine. In these lignites _Anodon_ and other fresh-water shells are found.