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 Raphiosaiirns ; 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 

 vertebrae, 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 Araucarise and Cycadeous plants, with living Ciavagellse, 

 Terebratulas, and Trigonias, 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 Hylseosaurus 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 new localities from which these specimens were 

 derived, observed that the name Iguanodon, by conveying the 

 idea of a gigantic Iguana, 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 

 vertebrae, 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 ail modern Lacertians, and approaches 

 nearer the crocodiles, but surpasses them in the development of 

 the ridge in question. A detailed 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 from the Isle of 



