Q6 Huxley — On a new Reptile from the Chalk-marl. 



right side is much more deeply hollowed in the same direction. 

 Furthermore, the anterior, convex, edgeis not straight, but is slightly 

 concave towards the left, and convex towards the right side ; while 

 the posterior, concave, edge is concave towards the right, and convex 

 towards the left side. The ridge which forms the posterior edge is 

 suddenly interrupted near the base of the spine by a deep notch, 

 (Fig. 1, a,) which probably received the anterior edge of the next 

 succeeding spine. The transverse diameter of the base of this spine 

 could not have been less than four inches when it was entire. 



I estimate that the more or less complete remains of nearly a 

 hundred scutes of the different forms now mentioned, must have 

 passed through my hands, and, as they all came from one small 

 area, they probably belonged to one animal. 



Such vertebras as have been obtained, are in a very fragmentaiy 

 state. The body of a dorsal vertebra is about 1'5 in. high, but 

 has a less width ; its length cannot have exceeded two inches. Its 

 articular ends are very slightly concave, and it is somewhat narrower 

 in the middle than at the ends. The neural canal is spacious, 

 being not less than one inch high. The neural spine appears to have 

 been low and inclined somewhat backwards. Another detached body 

 of a dorsal vertebrse is 2*1 in. long, 0*2 in. high, 1-85 in. wide at its 

 articular ends, and 1"5 wide in its centre. The sacrum of this 

 reptile would be very interesting, but no fragment of that part of its 

 skeleton has as yet made its appearance. Of the skull I possess 

 only a very much mutilated fragment, showing the basioccipital and 

 basisphenoid. The occipital condyle measures 1-4: transversely, or 

 has about the same diameter as that of the skull of a Crocodilus 

 hiporcatus, which measures 16 inches in length, from snout to 

 occiput. But it is more elongated transversely and excavated above 

 than in the Crocodile, and the exoccipitals enter more largely into 

 its composition. The Crocodilian disposition of the Eustachian tubes 

 is absent, and the carotids run up the side of the basisphenoid in 

 Lacertilian fashion. The sslla turcica has a well developed posterior 

 plate. 



Only three teeth have been found in connexion with these remains, 

 but one of them is in a very perfect state, and was readily detached 

 from the matrix, so as to be easily viewed from all sides, (Plate V. 

 Fig. 4, a, h, c). The crown is broken off from the fang, which 

 another specimen shows to be about as long as the crown and sub- 

 cylindrical. The crown is nearly 0*4: long, the greater diameter of 

 its base is 0-27, and the less about 0*2 ; it is shaped like a lance-head, 

 with an acute point and sharp edges ; these edges are notched in 

 such a manner that the crown exhibits eight serrations on each side 

 of its apex. The enlargement of the crown into its swollen base is 

 somewhat sudden, and takes place higher up on the one face of the 

 tooth than in the other, so that when the tooth is viewed from one 

 edge the one face appears concave and the other convex (Plate V. 

 Fig. 4, &). 



The most curious feature about this tooth, however, is its colour. 

 The ground hue of the crown is pale brown, but vertical lines of dark 



