MIDDLE EOCENE FORMATIONS OF FRANCE. Calcaire Grossier, upper and middle, B.1, Table—The upper division of this group consists in great part of beds of compact, fragile limestone, with some intercalated green marls. The shells in some parts are a mixture of _Cerithium, Cyclostoma,_ and _Corbula_; in others _Limnea, Cerithium, Paludina,_ etc. In the latter, the bones of reptiles and mammalia, _Palæotherium_ and _ Lophiodon,_ have been found. The middle division, or calcaire grossier proper, consists of a coarse limestone, often passing into sand. It contains the greater number of the fossil shells which characterise the Paris basin. No less than 400 distinct species have been procured from a single spot near Grignon, where they are imbedded in a calcareous sand, chiefly formed of comminuted shells, in which, nevertheless, individuals in a perfect state of preservation, both of marine, terrestrial, and fresh-water species, are mingled together. Some of the marine shells may have lived on the spot; but the _Cyclostoma_ and _Limnea,_ being land and fresh-water shells, must have been brought thither by rivers and currents, and the quantity of triturated shells implies considerable movement in the waters. Nothing is more striking in this assemblage of fossil testacea than the great proportion of species referable to the genus _ Cerithium_ (see p. 245). 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_ 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. In some parts of the calcaire grossier round Paris, certain beds occur of a stone used in building, and called by the French geologists “Miliolite limestone.” It is almost entirely made up of millions of microscopic shells, of the size of minute grains of sand, which all belong to the class Foraminifera. Examples of some of these are given in Figs. 219 to 221. As this miliolitic stone never occurs in the Faluns, or Upper Miocene strata of Brittany and Touraine, it often furnishes the geologist with a useful criterion for distinguishing the detached Eocene and Upper Miocene formations scattered over those and other adjoining provinces. The discovery of the remains of Palæotherium and other mammalia in some of the upper beds of the calcaire grossier shows that these land animals began to exist before the deposition of the overlying gypseous series had commenced. Fig. 219: Calcarina rarispina, Fig. 220: Spirolina stenostoma, Fig. 221: Triloculina inflata.