FEMUR OF THE IGUANODON. 



433 



muscles, extends down the middle of the anterior face, and diverging 

 towards the inner condyle, gradually disappears. The shaft terminates 

 below in two large, rounded, and laterally- 

 compressed condyles (c, d), which are sepa- f I 

 rated in front and behind by a deep groove 

 (e). Near the middle of the shaft, the 

 mesial, or inner edge, forms a compressed 

 ridge, which expands into an angular pro- 

 jection, or trochanter (b). Thus the upper 

 part of the femur may be known by the 

 presence of the upper trochanter (a) ; and 

 if that process is broken away, the frac- 

 tured surface indicating its position will be 

 detected. If a fragment of the middle part 

 of the shaft only is found, the flattened 

 angular spaces, and the submedian tro- 

 chanter (b), or the mark of its attachment, 

 will identify it. The lower extremity of 

 the femur may be distinguished by the 

 deep groove (e) between the condyles, both 

 in front and behind. The medullary cavity 

 is very large. 



42. Probable form and size 

 of the iguanodon. — From nume- 

 rous detached bones that have been 

 collected from various localities of 

 the Wealden, and with the aid of the 

 few specimens in which several are 

 collocated in the same block of stone, 

 the size and proportions of the body 

 and limbs of the Iguanodon have 

 been determined ; yet but a vague 

 idea of the form and appearance of 

 the original animal can be derived ^i™^- T £?££ 

 from the relics hitherto discovered. Ba,J - 

 For the great discrepancy between »»•«*•■«*»*— w**J 



,, , .Piii ff ' Upper trochanter. 



tne known parts of the skeleton, &, Middle trochanter. 



nnA , j. , , c, Inner, d, outer condyle. 



and the Corresponding bones in the ^Groove between the condyles. 



F F 



