ROOM III. THE MAIDSTONE IGUANODON. 307 



Antero-posterior diameter 1 inch. 



Transverse 2^ 



Vertical ........ If 



The impressions left by these two bones remain distinct on 

 the stone, and as, fortunately, I had moulds taken of them 

 when in my possession, casts of these important parts of the 

 skeleton may be restored. 1 



As the bones in the Maidstone Iguanodon have been 

 described when treating of the anatomical characters of the 

 several parts of the skeleton, it is unnecessary to extend 

 this notice of a specimen whose interest chiefly depends on 

 the collocation of the principal elements of the osteology of 

 the colossal reptile of the Wealden. 



PHYSIOLOGICAL INFERENCES AS TO THE STRUCTURE AND 

 ECONOMY OF THE IGUANODON. In instituting a comparison 

 between the maxillary organs of the Iguanodon, and those of 

 the existing herbivorous lizards, with the view of obtaining 



1 The Lignograph 65, is merely a diagram or plan to show the posi- 

 tion of the several parts, without any pretensions to accuracy, and in- 

 tended to assist the visitor in identifying the bones referred to in the 

 previous descriptions. The original drawing, from which the litho- 

 graph published in the " Monograph of the Palseontological Society " 

 was taken, was executed by Mr. Dinkel, with great care, when the spe- 

 cimen was in my museum at Brighton (see Appendix G.) ; I therefore 

 regret that the lithograph is a modified copy, and does not convey an 

 accurate idea of the original. The lithograph in my " Wonders of 

 Geology," sixth edition, PL III., is very faithful, but on too small a scale 

 to admit of anatomical details. 



The palaeontologist desirous of ascertaining the structure of the Igua- 

 nodon, and the relative proportions of the respective bones, will I fear 

 be embarrassed by the manifest difference between the measurements of 

 some of the bones given by me, and those by Professor Owen in the 

 " Monograph " referred to. The scale of Professor Owen's Plate XXXIII. 

 is mentioned to be " 2 inches to the foot " = ; and the bone which is 

 termed the ulna, (but which I believe to be a metacarpal bone,) is stated 

 to be eighteen inches long, (See " Monograph," p. 114) ; yet in the Plate 

 XXXI 1 1. this bone measures 2- inches, which is only equal to between 

 13 and 14 inches; a length which nearly agrees with that given by me, 

 namely, 14 inches. 



The "genuine worker" is therefore requested to judge for himself, 

 by a careful examination of the specimen; for there are several other 

 incongruities equally important ; for example, the Clavicle, which when 

 the specimen was in my possession measured 28 inches, is, according to 

 Professor Owen's table, nine inches longer, namely 37 inches. (" Mono- 

 graph," p. 113.) 



