256 THE BATH OOLITE PERIOD. CHAP. 



rises in a large hollow space above the neural canal. The anterior 

 zygapophysis is not well shewn in this specimen. 



In vertebrae somewhat farther along the back (the parapophysis 

 borne on the great lateral spine), the posterior zygapophysis is 

 observed in two examples, from which a restoration is attempted 

 in Diagram LXXXVII. on the same scale as the figure in Diagram 

 LXXXVI. 



Diagram LXXXVII. Posterior zygapophysis of Ceteosaurus. Scale one-tenth 



of nature. 



If this be compared with the corresponding part in megalosaurus 

 in Diagram LIX., with that of Ceteosaurus brevis (Owen, on 

 Wealden Fossils, Supplement I., 1857, Plate VIII.), and with that 

 of streptospondylus (Plate VII.), a general analogy will appear, 

 while all differ much from the crocodilian form. 



The specimen figured (Diagram LXXXVI.) measures, in its crushed 

 and incomplete state, 6'5 inches from back to front of the body ; 

 other examples of dorsals farther on, not so crushed as to conceal 

 the length, give 8-5 inches. The diameter of the largest is 8-5, and 

 the height is equal to the breadth ; the outline being a little sunk 

 under the neural canal. 



The neural canal is 2*4 inches high, and two inches wide. The 

 space between the neural canal and the zygapophysial articulation 

 is 5- 1 inches. In another specimen this space is 6-0 inches. From 

 the base of the neural canal to the summit of the neural spine, 

 21 inches; distance between the summits of the diapophyses, 18 

 inches. From the base (incomplete) of the vertebra to the summit 

 of the neural spine, 28-25 inches. The surfaces for the attachment 

 of the ribs are at a distance of twelve inches. The most unusual 

 features in these strange bones are the great broad head of the 

 neural spine (several fragments are larger than this) , and the high 

 and wide hollow interspace between the neural canal and the 

 anterior zygapophysis. Several other dorsals follow, none com- 

 plete," one of which is represented on the next page. 



