CRETACEOUS FORMATIONS. 113 



of the dorsal vertebrae ; the part of the bone which is prolonged backwards beyond 

 the articular part is slender, and terminates in an obtuse point. The right ilium, 

 which is overlapped by one of the clavicles, shows that the anterior end bends 

 outwards in the form of a thick tuberosity, and the expanded portion contributes by 

 its lower border the usual share in the formation of the acetabulum. 



The \mq> femora (T. XXXIV, /J?w«^r) well exemplify the characteristic peculiarities 

 of this bone in the Iguanodon : its inwardly projecting hemispheric head, its much 

 flattened trochanter, the compressed ridge-like process from the middle of the inner 

 surface of the shaft, and the deep and narrow fissure between the distal condyles. 

 This part of the femur had been figured and referred by Dr. Mantell to the Iguanodon, 

 in his ' Geology of the South-East of England,' Nov. 1 833, p. 310, pi. IV, figs. 3 and 4 ; 

 and the subsequent discovery of the Maidstone specimen confirmed the accuracy of 

 that determination. 



The bone which is figured in PL II, fig. 8 of the same work, as the tibia of the 

 Iguanodon, is also shown to be correctly so called by the Maidstone specimen, 

 T. XXXIII and T. XXXIV. 



The following are the dimensions of the principal and best-preserved bones in that 

 specimen : — 



Dorsal Vertebrce, 



Inches. Lines. 

 Antero-posterior diameter of centrum . . . . . . . 3 10 



Vertical diameter of articular end ........ 4 



Transverse diameter of ditto ........ 3 1 



From the base of the neurapophysis to the fore-part of that of the spinous 



process ............30 



From ditto ditto back part of ditto ... 4 



Antero-posterior extent of neural platform ...... 4 6 



Caudal Vertebra. 



Antero-posterior diameter of centrum ....... 2 5 



Vertical diameter of articular end ........ 2 5 



Transverse diameter of ditto . . . . . . . . • 111 



From the base of the neurapophysis to the fore-part of that of the spinous 



process ............ 1 3 



From ditto ditto back part of ditto ... 1 6 



Clavicle. 



Length of the bone . . . . • . * • • .37 



Breadth across the process at the broader end . . ... . . 8 



Breadth across tbe narrower end , . . . . . . .4 



15 



