378 FOSSIL REPTILES. 



which seems to have been herbivorous, the iguanodon^ and 

 has given, in the Philosophical Transactions for 1825, a most 

 interesting article on its teeth and bones. The sandstone of 

 Tilgate is a part of the iron-sand formation, which forms a 

 chain of hills stretching through Sussex in a west-north-west 

 direction from Hastings to Horsham. In various parts of its 

 course, but especially round Tilgate, it contains a quantity of 

 organic remains of various kinds. Mr. Mantell thus enume- 

 rates those which he considers to be characteristic of Tilgate 

 Forest. (See Geol. Trans. 1826, vol. ii. part 1, second series, 

 p. 134.) 



Stems of vegetables allied to the genus Cycas, and, perhaps, 

 Euphorbium. 



Leaves of a species of fern. 

 Plates and bones of turtles. 



Teeth and bones of crocodiles, and other saurian animals, 

 of an enormous magnitude. 

 Bones of birds. 

 Teeth and scales of fishes. 



Teeth of an unknown herbivorous reptile (the iguanodon), 

 differing from any hitherto discovered, either in a recent or 

 fossil state. Teeth of an animal of the lacertian tribe, resem- 

 bling those found at Stonesfield, near Oxford, and figured by 

 Lhwyd. 



So great is the difference between the teeth of the crocodile, 

 the megalosaurus, and plesiosaurus, and so much do they differ 

 from those of the other lizard tribes, that it is scarcely possible 

 to commit an error in their identification. But some other 

 teeth were discovered in the summer of 1822, in the sandstone 

 of Tilgate, which, with an obvious indication of herbivorous 

 characters, exhibited other peculiarities of so remarkable a 

 kind, as to arrest the attention of the most superficial observer, 

 and announce something of a very novel and interesting de* 

 scription. 



Mr. Mantell made a comparison of these teeth with those 



