ROOM III. LOWER JAW OF THE IGUANODON. 243 



imbedded, and who, although I was personally unknown to 

 him, in the true spirit of an ardent cultivator and liberal 

 promoter of science, placed it at my disposal, as the original 

 discoverer and investigator of the fossil saurians of the 

 Wealden ; a tribute of respect that I regard as a high reward 

 for my humble efforts to advance that department of natural 

 knowledge, to which I have devoted the leisure moments of a 

 life of professional toil. 



This specimen was found imbedded in a block of the fawn- 

 coloured sandstone which occurs interstratified with beds of 

 clay and limestone, throughout a considerable part of the 

 Wealden districts of the south-east of England ; fortunately 

 this stone is not very compact, so that the organic remains it 

 contains may be extricated by a skilful manipulator, with but 

 little difficulty. It consists of the dentary, and part of the 

 coronoid or complementary bone, of the right side, and is 

 entire at the anterior part ; but the posterior or opposite 

 extremity is imperfect, probably to the extent of several 

 inches. Its original relative position in the jaw will be under- 

 stood by a reference to Lign. 49, in which the peculiar con- 

 struction of the lower jaw in the Iguana is exemplified. 



LIGN 53 RIGHT SIDE OF THE LOWER JAW OP THE IGUAXODOV, FROM TILGATE 



FOREST, DISCOVERED BY CAPTAIX LAMBART BRICKENDEN, F.G S. 



( The inner aspect : } nat. size.) 



The specimen is represented of the natural size in the 

 " Philos. Trans, for 1848," PL XVI., of which Lign. 53, and 

 54, are reduced sketches ; its dimensions are as follow : 



Inches. 



Length from the front of the symphysis to the posterior 

 extremity of the bone * l 



Greatest width of the outer surface measured over the 

 convexity, from the lower margin to the upper al- 

 veolaredge 



