294 



PALAEONTOLOGY. 



the Iguanodon was distinguished by teeth, resembling in 

 shape those of the Iguana, but more so those of Scelidosaurus, 

 yet in structure differing from the teeth of that and every 

 other known reptile, and unequivocally indicating the former 

 existence in the Dinosaurian order of a gigantic representative 

 of the small group of living lizards which subsist on vegetable 

 substances. 



The important difference which the fossil teeth presented 

 in the form of their grinding surface was pointed out by 

 Cuvier,* of whose description Dr. Mantell adopted a con- 

 densed view in his Illustrations of the Geology of Sussex, 

 4to, 1827, p. 72. The combination of this dental distinction 

 with the vertebral and costal characters, which prove the 

 Iguanodon not to have belonged to the same group of Saurians 

 as that which includes the Iguana and other modern lizards, 



rendered it highly 

 desirable to ascer- 

 tain by the improved 

 modes of investigat- 

 ing dental structure, 

 the actual amount of 

 correspondence be- 

 tween the Iguanodon 

 and Iguana in this 

 respect. This has 

 been done in the 

 author's general de- 

 scription of the teeth 

 of reptiles, f from 

 which the following notice is abridged : — The teeth of the 

 Iguanodon (fig. 100), though resembling most closely those of 

 the Iguana, do not present an exact magnified image of them, 



* Ossemens Fossiles, 1824, vol. v., pt. ii., p. 351. 

 f Odontography, pt. ii., p. 249 ; Transactions of the British Association, 1838. 



Fig. 100. 



Front and side views of a tooth of the lower jaw 

 of the Iguanodon, nat. size. 



