THE IGUANODON AND HYLiEOSAURUS. 
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A. The right ilium. 
A'. Anterior prolongation of the same. 
A". Posterior extremity of the ilium, of which several inches are wanting. 
A'". Crest or upper margin of the same. 
A"". Remains of the neck of the ilium. 
PLATE XXVII. 
This fossil consists of the four distal anchylosed vertebrae of a sacrum belonging 
either to the Hylaeosaurus or Iguanodon {natural size). Collected by 
Captain Lambart Brickenden, F.G.S. 
Fig. 2. The inferior or visceral aspect. 
Fig. 3. The side or lateral aspect. 
3, 4. The two middle slender vertebrae. 
5, 6. The tv/o larger and posterior vertebrae. 
h. Sacral ribs. 
j. The spinal canal. 
k. Line of intervertebral anchylosis. 
b. Bases of the neural laminae. 
PLATE XXVIII. 
V ertebroe of the Iguanodon. 
Fig. 4. Cervical vertebra from Brook Bay : this specimen is somewhat compressed 
vertically, so as to appear wider and more elliptical transversely than 
natural. 
V. Inferior view. 
4*. Upper view. 
4^ Lateral view. 
The several parts in this and the other vertebrae are indicated by the following 
signs : — 
a. The body or centrum. 
d. The anterior articulating surface of the same. 
a". The posterior — . 
h. The neural arch. 
c. The spinous process. 
d. Superior transverse process. 
e. Inferior transverse process. 
f. Anterior oblique process. 
g. Posterior oblique process. 
h. Rib or costal process. 
MDCCCXLIX. 2 R 
