iisitiien 
| Proceedings of the British Association. 331 
were referred to a small genus of Lacertians from the chalk for- 
mation in Cambridge and Maidstone, to which Prof. O, had given 
the name Raphiosaurus ; a portion of the lower jaw containing 
twenty two awl-shaped teeth, and another specimen consisting 
of twenty dorsal, two lumbar, two sacral, and a few caudal 
vertebra, with the pelvic bones, were described. Part of the 
lower jaw, with teeth, of another lizard about as large as the 
Iguana, was described as occurring in the eocene sand under the 
red crag at Kyson. Remains of a Lacertian were next described 
from the celebrated oolite at Stonesfield. The structure of these 
bones indicates a close affinity to the scincoid lizards, the largest 
forms of which now exist in Australia, where they are associated 
with Araucarie and Cycadeous plants, with living Clavagelle, 
Terebratule, and Trigonia, and with the peculiar marsupial 
quadrupeds, the remains of all which forms of organized beings 
characterize the same stratum and locality as does the present 
extinct Lacertian. Prof. O. next proceeded to notice the more 
remarkable and gigantic forms of terrestrial Saurians of the same 
period, from the eocene tertiary to the oolites. Of these, the 
Megalosaurus, Iguanodon, and Hyleosaurus had been described 
by their original discoverer, Dr. Mantell, and by Dr. Buckland in 
his ‘ Bridgewater Treatise.’ Prof. O. after pointing out additional 
peculiarities of structure discovered in specimens subsequently 
found, and the uew localities from which these specimens were 
derived, observed that the name Iguanodon, by conveying the 
idea of a gigantic Jguana, created an erroneous idea of its affin- 
ities. No existing lizard differed more from the Iguana than did 
the Iguanodon, in the absence of the ball-and-socket joint of the 
vertebree, and likewise in the structure of the teeth, which is 
characterized in the gigantic extinct herbivorous reptile by nu- 
merous parallel medullary canals. The femur of the Iguanodon, 
in the process continued from the inner side, near the upper third 
of the bone, deviates from all modern Lacertians, and approaches 
nearer the crocodiles, but surpasses them in the development of 
the ridge in question. Adetailed description of the skeleton, 
founded upon nearly all the remains of the Iguanodon yet dis- 
‘covered, was next given; the form of the claw-bones of ‘the 
Iguanodon, and especially of some enormous ones recently dis- 
covered with other bones at Horsham, was described, and from 
a comparison of these with other specimens fromthe Isle of 
