At some points, as at Louans, south of Tours, the shells are stained of a ferruginous colour, not unlike that of the red crag of Suffolk. The species are, for the most part, marine, but a few of them belong to land and fluviatile genera. Among the former, _Helix turonensis_ (fig. 45. p. 30.) is the most abundant. Remains of terrestrial quadrupeds are here and there intermixed, belonging to the genera Deinotherium, Mastodon, Rhinoceros, Hippopotamus, Chaeropotamus, Dichobune, Deer, and others, and these are accompanied by cetacea, such as the Lamantine, Morse, Sea-calf, and Dolphin, all of extinct species. Professor E. Forbes, after studying the fossil testacea which I obtained from these beds; informs me that he has no doubt they were formed partly on the shore itself at the level of low water, and partly at very moderate depths, not exceeding 10 fathoms below that level. The molluscous fauna of the "faluns" is on the whole much more littoral than that of the red and coralline crag of Suffolk, and implies a shallower sea. It is, moreover, contrasted with the Suffolk crag by the indications it affords of an extra-European climate. Thus it contains seven species of _Cypraea_, some larger than any existing cowry of the Mediterranean, several species of _Oliva_, _Ancillaria_, _Mitra_, _Terebra_, _Pyrula_, _Fasciolaria_, and _Conus_. Of the cones there are no less than eight species, some very large, whereas the only European cone is of diminutive size. The genus _Nerita_, and many others, are also represented by individuals of a type now characteristic of equatorial seas, and wholly unlike any Mediterranean forms. These proofs of a more elevated temperature seem to imply the higher antiquity of the faluns as compared with the Suffolk crag, and are in perfect accordance with the fact of the smaller proportion of testacea of recent species found in the faluns. Out of 290 species of shells, collected by myself, in 1840, at Pontlevoy, Louans, Bossee, and other villages 20 miles south of Tours; and at Savigne, about 15 miles north-west of that place; 72 only could be identified with recent species, which is in the proportion of 25 per cent. A large number of the 290 species are common to all the localities, those peculiar to each not being more numerous than we might expect to find in different bays of the same sea.