P.OOM III. METATARSALS OF THE IGUANODON. 295 



It is the thigh bones, marked Nos. 4 and 5, which Pro- 

 fessor Owen observes " we might conclude to be humeri" 

 (" Brit. Rep." p. 137.) And in the next page he describes 

 a bone (an undoubted femur) that corresponds " in form 

 with the bones Nos. 4 and 5 of the Mantellian Collection." 

 Professor Owen then observes " As the absence of the deep 

 fissure between the condyles of the femur is repeated in the 

 humerus of the Iguana, so may its presence be repeated in the 

 humerus of the Iguanodon" p. 138. The remarks of a cor- 

 respondent, Mr. Holmes, are then inserted to " support the 

 view I had taken of their nature." (See note to p. 286.) 



On the narrow front shelf (ante, p. 227,) there is a femur of 

 a very young Iguanodon, but nine inches in length. 



BOXES OF THE HIND FEET ; metotarsals, phalangeals, and 

 unguals. The bones composing the hind foot of the Iguano- 

 don, have already been alluded to, as presenting in their 

 massive proportions the characters of mammalian rather than 

 of reptilian metatarsals. No specimens have come under my 

 notice that could with certainty be assigned to the tarsus. 

 I have some very massive and solid bones of a cuboidal form, 

 but much waterworn, that were collected from the shore at 

 Sandown Bay, whence the gigantic phalangeal, figured by Dr. 

 Buckland in " Geol. Trans.," was obtained ; and these speci- 

 mens may possibly belong to the tarsus of the Iguanodon. 



Metatarsals. Wall-case C, lower shelf. A considerable 

 number of metatarsals belonging to animals of various ages 

 and magnitude have been collected ; and there are some fine 

 specimens in the Case before us. They are easily recognised 

 by their peculiar form, as shown in Lign. 63, fig. 8. 



The proximal extremity is very much compressed laterally, 

 the vertical diameter being thrice that of the transverse ; the 

 articular surface is almost flat. The bone is contracted in the 

 middle, and forms at the distal end a bold trochlear articulation 

 divided by a vertical depression. 



The large metatarsal on this shelf is figured in " Fossils of 

 Tilgate Forest," PL XV. fig. 8 ; it has the following propor- 

 tions : 



Length 10 inches. 



Proximal end ; vertical diameter ... 7 



transverse diameter . . 2| 



Distal end ; vertical diameter .... 4^ 

 transverse diameter ... 3^ 



