Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/508

 3. Notes on some Fossil Remainss of a Gavial-like Saurian from KiMMERiDGE Bay, collected by J. C. Mansel, Esq., establishing its identity with Cuvier's Deuxieme Gavial d'Honfleur, Tete a museau plus court (Steneosaurus rostro-minor of Geoffrey St.- Hilaire, 1825), and with Quenstedt's Dakosaurus. By J. W. HuLKE, Esq., F.R.S., F.G.S. [Plates XVII. & XVIII.]

The fossils which form the subject of this note consist of part of a lower jaw, with teeth and vertebree, imbedded in hard pyritic claystone, lent me by J. C. Mansel, Esq., and of parts of the upper and lower jaws, with several teeth in situ and loose, portions of vertebrae and of ribs, a femur, and some other bones, which, owing to their fragmentary and crushed condition, I have not been able to identify, in the British Museum. As received from Mr. Mansel, the bones in the British Museum were nearly hidden in large masses of very hard stone containing, as is usual in Kimmeridge fossils, much pyrites, which made it very difficult to extricate them ; but this has been successfully accomplished, and the severed pieces have been very skilfully joined by Mr. Davies, to whom I am glad to take this opportunity of expressing my obligation for much valuable assistance.

Description — Upper Jaw. — Of this the British Museum has the extreme end of the snout, comprising the symphysis, with about 4 inches of both intermaxillae, forming the antero-lateral boundary of an undivided terminal nostril, which has a laterally compressed oval form, and is not swollen at the sides as in the living Gavials and in the extinct Teleosaurs, The oval nostril is indented in front by a slightly overhanging, medial, tubercular production of the symphysis. A thin seam of stone marks the open intermaxillary suture. The outer border of the upper surface of the portions of the intermaxillae bounding the nostril makes a blunt ridge with the nearly vertical outer surface, from which the upper surface slants in-wards and downwards to the inner surface ; and this latter slants downwards and outwards, so as to overhang the floor of the nostril, with which it makes an angle of rather more than 45°.

The alveolar border of the right intermaxilla has been laid bare ; it contains three alveoli ; and the hard palate has been traced to within .9 inch of the symphysis, which shows that the palatine processes of the intermaxillaries subtend the greater part of the nostril, and that the prepalatine foramen is proportionately lessened, a point of resemblance to the living Gavial in which this latter differs from crocodiles proper. The outer surface of the intermaxillae bends evenly outwards and backwards from the symphysis. There is not any indication of a notch for the passage of the fourth tooth ; and, as far as I can judge from this fragment, the snout tapered regularly, ending bluntly.

There is another fragment, 5-1/2 inches long, which belongs, perhaps, to the upper maxilla. It contains five alveoli, four of which include portions of teeth. The outer surface is moderately convex ;