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.
The crocodiles continue to make their appearance in these schists, and always of the long-muzzled or rostrated kind. M. de Sœmmering has described one (the Crocodilus priscus), the entire skeleton of a small individual of which was found nearly in as good a state of preservation, as it could have been in our cabinets.[256] It is one of those which most resemble the present gavial of the Ganges; the anterior or united part of its lower jaw, however, is less elongated; its lower teeth are alternately and regularly longer and shorter. It has ten vertebræ in the tail.
But the most remarkable animals which these limestone slates contain, are the flying lizards, which I have named Pterodactyli.
They are reptiles whose principal characters are, a very short tail, a very long neck, the muzzle much elongated, and armed with sharp teeth; the legs also long, and one of the toes of the anterior extremity excessively elongated, having probably served for the attachment of a membrane adapted for supporting them in the air, accompanied with four other toes of ordinary size, terminated by hooked claws. One of these strange animals, whose appearance would be frightful did they occur alive at the present day, may have been of the size of a thrush[257], the other of that of a common bat[258]; but it would appear from some fragments that larger species had existed[259].