Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/274

 Dimensions.

EXPLANATION OF PLATE IX.

Fig. 1. Under surface of skull of Steneosaurus Manselii.

a. Anterior palatine foramen. b. Praemaxillary -maxillary suture. c. Anterior extremity of pterygo-maxillary foramen. d. Basisphenoid.

2. Upper surface of skull.

a. The triangular bones corresponding to those lettered a a in Cuvier's figure of upper surface of snout of Gavial tete a museau plus court, b. The nasals. c. Their anterior termination in the nostril. d. The orbit. e. Parietal crest.

5. Note on some Teeth associated with Two Fragments of a Jaw from Kimmeridge Bay. By J. W. Hulke, Esq., F.R.S., F.G.S.

Amongst many other Kimmeridge fossils which Mr. J. C. Mansel has intrusted to me for examination are two pieces of a long, slender snout, not unlike that of a long -beaked Ichthyosaurus, but too fragmentary and crushed to allow of their certain identification.

The teeth differ from those of all the fossil fish and reptiles in the British Museum with which I have been able to compare them. They are peculiar in the great development of the cementum, which gives the fang the appearance of being inserted in a bulbous sheath. The base of the tooth resembles a little bulb, from the top of which a slightly curved, cylindrical, conical, and polished crown protrudes. The average length of the teeth is nearly 5-1/2 lines (English), of which about 3′″ belong to the neck and crown. The diameter of the neck and of the neighbouring part of the crown is about 1-1/6′″, while that of the bulbous fang reaches 2-1/6′″. The crowns are dark brown, polished, and smooth, and their transverse section is circular. They are composed of a simple tubular