XX. — On the discovery of Fossil Bones of the Iguanodon, in the Iron 

 Sand of the Wealden Formation in the Isle of Wight, and in the 

 Isle of Purbeck. 



By the Rev. WILLIAM BUCKLAND, D.D., V.P.G.S. F.R.S. F.L.S. 



(professor of geology and mineralogy in the university of oxford.) 



[Read December 4, 1829.] 



We are indebted to the researches of Mr. Mantel!* for our knowledge ot 

 the existence of that curious and most gigantic herbivorous reptile the Igua- 

 nodon f. 



The localities in which he discovered it are limited to the Hastings sand, 

 or Wealden formation in Tilgate Forest, at the west extremity of which di- 

 strict are the quarries of Headfold Wood Common, where was found the enor- 

 mous femur described by Mr. Murchison in the Geological Transactions;};, as 

 being three feet seven inches long, and probably derived from this animal. 



In the course of this year, 1829, I have ascertained its presence in three 

 other localities, which are important, not only in relation to the history of 

 this singular reptile, but as tending still further to connect the geological 

 structure of those parts of the Isle of Wight and Isle of Purbeck wherein it 

 occurs, with the Hastings sand, ^. e. the iron sand of the Weald of Sussex and 

 Kent. 



I. Iguanodon at two new localities in the Isle of Wight. 



The first of these new localities is on the south coast of the Isle of Wight, 

 in the iron sand which forms the shore, a little east of Sandown Fort, between 

 high and low water. The most remarkable specimen I possess from thence 



* Philosophical Transactions, 182.5, Part I. p. 179 ; also, Illustrations of the Geology of Sussex, 

 with Figures of the Fossils of Tilgate Forest, 1827, p. 71. 



\ Mr. Mantel! has calculated the dimensions of tlie Iguanodon. on comparing the proportions 



of eight different bones from various parts of the skeleton with tnose of the recent Iguana, to be 



as follows : — 



Teet. 

 Length from snout to end of tail 70 



Length of tail 52§ 



Circumference of body 1 li 



It does not, however, follow that the proportions of the same parts in different genera are the same. 



X Second Series, vol. ii. Part I. p. 104, Plate XV. fig. 9. 



