422 



THE WONDERS OF GEOLOGY. Lect. IV. 



apparently to the same species (M. Bucklandi) as that 

 of Stonesfield. The tooth of this reptile (Lign. 101) is 

 distinguishable by its sabre-like form, conical laterally 

 compressed crown, and finely serrated trenchant edges. 

 From this structure of the tooth it may be inferred that the 

 Megalosaurus was carnivorous ; its length is estimated at 

 nearly thirty feet. 



37. The Iguanodon.* — Soon after my first discovery 

 of remains of large vertebrated animals in the strata of 

 Tilgate Forest, some teeth of a very remarkable character 

 particularly engaged my attention, from their dissimilarity 

 to any that had previously come under my notice. Even 

 the quarrymen, who had been accustomed to collect the 

 teeth of fishes and other relics of that nature, had not 

 observed them, until shown three or four mutilated speci- 

 mens, which I had extricated from a block of stone on the 

 road-side. Attention having thus been directed to the 

 subject, additional examples were soon discovered ; and at 

 length I obtained a series of teeth in various conditions, 

 from the pointed unused tooth of the young reptile {Lign. 

 102, fig. 2), to the obtuse, worn, flat crown of the adult 

 {Lign. 104). From the resemblance in the form of the 

 perfect tooth to that of the Iguana, f a terrestrial lizard of 



* Medals of Creation, vol. ii. p. 739. Brit. Assoc. Eeports for 1841, 

 p. 120. 



+ The Iguanas are land lizards, which inhabit many parts of 

 America and the West Indies, and are rarely met with north or south 

 of the tropics. They are from three to five feet in length, and feed on 

 insects and vegetables, climbing trees, and chipping off the tender 

 shoots. They nestle in the hollows of rocks, and deposit their eggs, 

 which are like those of turtles, in the sands or banks of rivers. The 

 Iguana is furnished with a row of very small, closely-set, pointed 

 teeth, with serrated edges, which have no distinct alveoli or sockets, 

 but are attached at the base, and by the outer surfaces of the fangs 

 to the jaw ; the alveolar process forms an external parapet, but there 

 is no internal bony covering. The new teeth do not, as in the croco- 



