332 Proceedings of the British Association. 
Wight, and with those preserved in the slab containing the Maid- 
stone Iguanodon, Prof. O. stated it to be his opinion, that the 
animal did not possess the peculiarity of having the fore legs pro- 
vided with compressed, and the hind legs with depressed claws, 
but that the narrow compressed curved claws occasionally found 
in the Wealden, belonged to another extinct reptile. ‘This sec- 
tion of the Report concluded with a notice of all the British 
localities, and the strata in which those remains had been discov- 
ered. ‘I'he anatomical peculiarities of the Hylzosaurus, another 
large extinct reptile of the Wealden clay, discovered by Dr. Man- 
tell, were next described; and an account of the microscopical 
structure of the dermal bones was given. ‘This remarkable rep- 
tile combines the sub-biconcave structure of the vertebree, with 
crocodilian scute, and a plesiosauroid form of the scapular arch. 
The teeth not uncommonly found in the Wealden strata, for- 
merly supposed to belong to the Phyiosaurus cylindricodon of 
Jaeger, and more recently to the genus Rhopalodon of Fischer 
de Waldheim, Mr. O. showed to be quite distinct from both, and 
stated that if they were not the teeth of the Hyleosaur, they 
must belong to some unknown genus of Lacertine Saurian. The 
remains of the genera T'hecodon and Palgosaur, from the mag- 
nesian conglomerates near Bristol, and of the genus Cladeiodon 
from the Keuper sandstone of Warwickshire, were next described. 
These were the most ancient of the Saurians yet discovered in 
Great Britain, and although they differ from modern Lacertians 
in the implantation of their teeth in distinct sockets, agreed with 
them in the form and structure of the teeth. The last genus of 
Saurians described, (Rhiynchosaurus, O.) is new to science, and 
the remarkable peculiarities of its cranial anatomy, together with 
its vertebral characters, and the structure of the ribs, and some of 
_the long bones, were given in detail. Characters of the croco- 
dile, lizard and tortoise were combined in the forms and connex- 
ions of the bones of the skull, a nearly entire specimen of which 
had been transmitted by Dr. O. Ward, of Shrewsbury, to Prof. 
Owen from the Grinsill quarries of the new red sandstone, where 
the foot prints of a reptile agreeing in size with the Rhynchosat- 
rus were not uncommon. Reasons were adduced showing the 
high probability that they were the foot prints of the Rhyn- 
chosaurus: they differ in shape from those of the Chirotherium, 
which were shown, in the concluding part of the Report, to be- 
