These two genera are found everywhere in the lias: they were discovered in England, where this rock is exposed in cliffs of great extent; but they have also been found since in France and Germany. Along with these had lived two species of Crocodiles, the bones of which are also found deposited in the lias, among ammonites, terebratulæ, and other shells of that ancient sea. We have skeletons of them in our cliffs at Honfleur, where the remains are found, from which I have drawn up their characters.[252] One of these species, the _Long-beaked Gavial_, has the muzzle longer, and the head more narrow, than the gavial or long-beaked crocodile of the Ganges; the bodies of its vertebræ are convex before, while in our crocodiles of the present day they are so behind. It has been found in the lias deposits of Franconia, as well as in those of France. A second species, the _Short-beaked Gavial_, has the muzzle of ordinary length, less attenuated than the gavial of the Ganges, but more so than our crocodiles of St Domingo. Its vertebræ are slightly concave at each of their extremities. But these crocodiles are not the only ones which have been deposited in the strata of these secondary limestones. The beautiful oolite quarries of Caen have presented a very remarkable one, the muzzle of which is as long and more pointed than that of the long-beaked gavial, and its head more dilated behind, with wider temporal fossæ. Its stony scales, marked with small round cavities, must have rendered it the best defended of all the crocodiles.[253] Its lower teeth are alternately longer and shorter. There is still another in the oolite of England; but there have only been found some portions of its cranium, which do not suffice to afford a complete idea of it.[254] Another very remarkable genus of reptiles, the remains of which, although they are also found beyond the limits of the lias concretion, are especially abundant in the oolite and upper sands, is the _megalosaurus_, justly so named, for, along with the forms of the lizards, and particularly of the monitors, of which it has also the sharp-edged and dentated teeth, it presents so enormous a size, that if we suppose it to have possessed the proportions of the monitors, it must have exceeded seventy feet in length. It was, in fact, a lizard of the size of a whale.[255] It was discovered by Mr Buckland in England; but we have it also in France; and in Germany there are found bones, if not of the same species, at least of a species which can be referred to no other genus. It is to M. Sœmmering that we owe the first description of this last. He discovered the bones in strata lying above the oolite, in those limestone-schists of Franconia, long celebrated for the numerous fossil remains which they furnished to the cabinets of the curious, and which will be still more celebrated for the services which their employment in lithography render to the arts and sciences.