much more carefully executed than Quenstedt's, might have been drawn from one of our crowns, so complete is the resemblance.
The teeth of the Kimmeridge Saurian, like those of Dakosaurus, are slightly incurved, slightly backward-curved, laterally compressed, and unequally convex. They have a serrated front and back cutting edge, and they are finely striated. They are stouter than the teeth of Megalosaurus ; their curve is also less sickle-like ; and the serrature of their trenchant ridges is less coarse than that of this Dinosaur.
But, because comparison with actual specimens is more satisfactory than that with descriptions, however close to nature these may be, I have compared our teeth with other Dakosaurian teeth in the British Museum, and I have found them to be specifically identical*.
IV. That Dakosaurus is probably the same as Cuvier's " deuxieme Gavial de Honfleur, tete a museau plus court," follows as the necessary consequence of the II. and III. of these conclusions, because, if this Kimmeridge crocodilian is identical with each of these, they must be identical with each other.
If these conclusions be ultimately proved correct, I would propose to retain Geoffroy St.-Hiliare's original name Steneosaurus rostrominor, to the exclusion of all given subsequently to his Memoir of 1825.
Note. — Since this paper was written, a further examination of the fossils presented to the British Museum has led to the discovery of a considerable part of the skull, with the complete snout, of this Kimmeridge crocodilian. I shall take an early opportunity of communicating a description of it to the Society. — J. W. H., Oct. 17, 1868.
EXPLANATION OF PLATES.
Plate XVII.
Fig. 1. Upper view of end of upper jaw of the Kimmeridge Gavial-like Crocodile, showing front half of subterminal nostril.
2. Side view of the same.
3. Posterior view of the same.
4. Outer view of right half of lower jaw of the same†. a, rib ; b, part of the femur ; c, part of the left half of the lower jaw, reversed. (This last I at first conjectured might be a crushed piece of the upper jaw.)
Plate XVIII.
Figs. 1 & 2. Side and front views of the neural arch and spine of a vertebra. a, prezygapophysis.
3. A trunk- vertebra, showing the anterior articular surface, the neural canal, and the long transverse process.
4. Side view of an early dorsal vertebra. There is a costal facet on the anterior margin of the transverse process near its root.
- I greatly regret not to have had the advantage of seeing in print Mr. Mason
Wood's paper on Dakosaurus, read in the early part of this session — the more so that, although present on the evening on which it was communicated to the Society, my mind being preoccupied by another subject, I did not give Mr. Wood's paper the attention it deserved.
† As the portions of this jaw entrusted to me by Mr. Mansel have been found to fit those in the British Museum, the jaw is shown in a single drawing after restoration.
