ROOM III. METACARPALS OF THE IGUANODON. 289 



but with the supposed radius of the Maidstone Iguanodon, 

 I lost the sole relic that could reasonably be referred to 

 that member of the anterior extremity. The only specimens 

 in the Museum that appear to belong to the fore-arm of the 

 Iguanodon, are the two small subcylindrical bones of a jet 

 black colour, that are affixed to the left hand side of Case C, 

 above the middle shelf. These were dug up from a bed of 

 weald clay near Eusper in the west of Sussex, with many 

 bones of a young Iguanodon ; I have a beautiful femur, 14 

 inches long, that was found with them. These fossils are, 

 however, too imperfect to admit of satisfactory interpretation, 

 till some clue is obtained as to their nature from more in- 

 structive specimens. 



Metacarpals. I have not seen any bones that could be 

 ascribed to the carpus ; but of metacarpals several have been 

 found, which are unquestionably referable to the Iguanodon. 

 The two fine metacarpals in the Maidstone Iguanodon (Lign. 

 65, No. 6) appear to me decisive on this point ; an outline 

 of one of these is given in Lign. 63, fig. 4. These bones lie 

 in close contact, and though somewhat distorted by com- 

 pression (as are all the bones in that specimen), still their 

 characters are well defined. A transverse* section of one of 

 them is shown, Lign. 63, fig. 4, a ; in chiselling away the sur- 

 rounding stone, one of these metacarpals broke transversely, 

 and became detached, and a drawing was made before it was 

 replaced and cemented in its original situation. 



When I had ascertained that the supposed radius was the 

 humerus, it occurred to me that the two bdnes in question 

 might be the radius and ulna; but upon repairing to the 

 Museum, and examining the specimen anew, I found that 

 my original interpretation was the true one; as the intelli- 

 gent visitor may convince himself by a careful inspection, for 

 the extremities of both bones are exactly alike. The proximal 

 ends, which are distinctly visible on the side of the block of 

 stone in which they are imbedded, are in close contact, and " 

 both present the same form ; there is not the slightest differ- 

 ence between them ; they closely resemble those of the 

 metatarsals : that is, they are compressed laterally, are higher 

 than wide, and have a nearly flat articular surface. The 

 shafts are subcylindrical, long, and slender, and the distal 

 ends form two well-marked trochlear articulations. If they 



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