30 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 23, 



Twenty-one teeth occupy a space of 8 inches. The length of a 

 fang slightly exceeds -3", the diameter (including the capsule) aver- 

 ages "3", and that of the dentinal cylinder minus its investing cap- 

 sule -IS". The apices of aU. the crowns are broken off, so that the 

 entire length of the teeth is not determinable. 



In their form and structure these teeth repeat so closely the 

 characters of those of the Kimmeridge Entliekiodon as to suggest the 

 great probability of their both belonging to the same genus. My 

 note on EntheTciodon* , communicated last session, noticed the resem- 

 blance of its teeth and of the mode of their attachment to the jaw 

 to those of Ichthyosaurus ; but my material was too imperfect to 

 justify me in certainly referring it to that genus. I have now, how- 

 ever, indisputable evidence that it is a true Ichthyosaurus ; and this 

 being so, the similarity of the dental characters of this Gozo mandi- 

 ble to those of Enthekiodon affords a strong presumption that it also 

 is Ichthyosaurian. 



Cbocodilits gaudensis. 



The skull is in form elongated and sub triangular. Its sides eon- 

 verge regularly from the posterior and outer angles of the quadrate 

 bones to the 8th tooth, counted from behind. From this they are 

 nearly parallel, to the 14th tooth, in front of which the snout is 

 slightly contracted where the premaxiUo -maxillary suture crosses 

 its alveolar border. The end of the snout, including the external 

 nostril, is wanting. 



The syncipital area is a nearly flat oblong, measuring transversely 

 along its posterior border 5"-4, along its anterior border (a line con- 

 necting the anterior and outer angles of the postfrontal bones) 5", 

 and from front to back 3"-2. The entire surface of this area is sym- 

 metrically pitted. In its frontal part, which is hollow transversely 

 and plane axially, the pits are grouped in lines diverging from the 

 axis of the skull, and there is a large remarkable pit in each pos- 

 terior angle of the area. 



The supratemporal fossae are very large, and have an angulated 

 pentahedral shape. Their transverse diameter, shghtly larger than 

 the others, is 1"'8. The intervening parietal bone has a minimum 

 width under "1". 



The interorbital space is narrow, hoUow transversely, plane axially, 

 and less strongly pitted than the syncipital area. 



The orbits are large, their contour is subtriangular, incomplete 

 behind ; they look directly upwards ; and their long diameter is 

 directed from behind forwards and inwards. The outer, front, and 

 inner part of their margin is raised ; and the front part is channelled 

 by two grooves, of which one descends longitudinally on the pre- 

 frontal bone, and the other along the junction of the prefrontal and 

 lachrymal bones. 



The nasal bones posteriorly reach the level of a line joining the 

 anterior angles of the orbits, and, descending the snout in the form 



* Quart. Journ. Geol. Soc. vol. xxvi. p. 172. 



