SUPPLEMENT (No. II)* 



TO THE 



MONOGRAPH 



ON 



THE FOSSIL REPTILIA 



OF 



THE CRETACEOUS FORMATIONS. 



Order— DINOSAURIA, Owen. 

 Genus — Iguanodon, Mantell. 



Dentition of the Upjjer and Lower Jaws (Tab. VII). 



In the year 1858 a considerable part of the skeleton of an Iguanodon was dis- 

 covered in the Lower Greensand formation at Black Gang Chine, Isle of Wight. 



The workmen disposed of various parts of it, as opportunities offered ; 

 and before steps could be taken to secure the whole for the British Museum, 

 portions of jaws and teeth had passed into the hands of private collectors. From 

 the best account of the discovery that I could collect, it appeared that the entire 

 cranium, somewhat dislocated, had been brought to light by the quarrymen ; but 

 the bones were in a peculiarly fragile, crumbly state, and only the firmer parts of 

 the jaws, lodging the teeth, were secured, and these portions in fragments. Some 

 of them, of both upper and lower jaws, are now in the British Museum ; and 

 learning that other portions had been acquired by George Robbins, Esq., F.G.S., 

 of Castle, near Bath, I addressed a letter to that gentleman, who very kindly 

 brought his specimens to London, and liberally placed them in my hands for de- 

 scription. The largest fragment fitted on to another portion of the jaw in the 

 British Museum, adding to its value as an illustration of the most interesting of 

 the hard parts of the Iguanodon. It consisted of a fragment of the left upper jaw, 

 with three teeth ; there were also three fragments of the left ramus of the lower 

 jaw, with one or more teeth in each. 



The germs of the new teeth are developed, in all Saurians, as is well known, 

 on the inner or mesial side of the base of the old teeth. f One of the teeth in the 



* This Memoir was given as " Supplement (No. II) to the Monograph on the Iguanodon," in the 

 1858 volume. 



t Of this character Professor Melville ably availed himself in determining the upper and lower teeth of 

 the Iguanodon, in the joint memoir, by Dr. Mantell and himself, in the 'Philos. Trans.' for IS IS. 



