smaller animals occur often in a state of preservation so peculiar and partial as to excite the curiosity of even the untaught workmen. Only half the skeleton is present. The limbs and ribs of the under side are found lying in nearly their proper places; while of the limbs and ribs of the upper side usually not a trace can be detected,--even the upper side of the skull is often awanting. It-would almost seem as if some pre-Adamite butcher had divided the carcasses longitudinally, and carried away with him all the upper halves. The reading of the enigma seems to be, that when the creatures lay down and died, the gypsum in which their remains occur was soft enough to permit their under sides to sink into it, and that then gradually hardening, it kept the bones in their places; while the uncovered upper sides, exposed to the disintegrating influences, either mouldered away piecemeal, or were removed by accident. The bones of the larger animals of the basin are usually found detached; and ere they could be reconstructed into perfect skeletons, they taxed the extraordinary powers of the greatest of comparative anatomists. Rather more than twenty different species of extinct mammals have been detected in the Paris basin,--not a great number, it may be thought; and yet for so limited a locality we may deem it not a very small one, when we take into account the fact that all our native mammals of Britain and Ireland amount (according to Fleming), if we except the Cetaceæ and the seals, to but forty species. [Illustration: Fig 71. ANIMALS OF THE PARIS BASIN.[15] (_Eocene._)] [Illustration: Fig. 72. DINOTHERIUM GIGANTEUM. (_Miocene._)]