332 BRITISH FOSSIL REPTILES. 



Borml vpiiebra. PI. 24. Nat. size. 



The Megalosaurus departs, perhaps even more than does the Iguanodon, from the 

 existing Crocodiles, Monitors and Lizards, in its vertebral characters. The articulating 

 surfaces of the vertebral bodies are very slightl)' concave, indeed almost flat, presenting 

 in that respect the type of the Amphicoclian Crocodiles : the non-articular surface is 

 remarkably smooth and polished. The centrum is much contracted in the middle, 

 presenting a deep concave outline of the under surface : the margins of the expanded 

 articular extremities are thick and rounded off. The almost cylindrical section of the 

 middle part of the vertebra arises from its being nipped in, as it were, by a more or 

 less deep longitudinal fossa on each side, just below the base of the neural arch ; the 

 centrum, however, slightly expanding above the fossa to support the arch. 



The length of the base of the neurapophysis is nearly equal to that of the centrum ; 

 the suture is persistent, as in Crocodiles ; its course is undulating, and it rises in the 

 middle of the centrum. The neurapophysis ascends and inclines outwards, to form, at a 

 height above the centrum equal to three fourths its vertical diameter, the margin of a 

 broad platform of bone, from the sides of which the upper transverse processes (diapo- 

 physes) are developed, and from the middle of the upper surface the spinous process. 

 A recent discovery has shown the extraordinary development of the latter 

 apophysis in some of the anterior dorsal vertebrae. 



In the Wealden deposits at Battle, Sussex, a large nodule of the ferruginous clay 

 had been formed and consolidated around a portion of the skeleton of a Me^alosatirus 

 consisting of some anterior thoracic vertebrte. In the state in which this 

 nodule was submitted to my examination, three almost entire and consecutive 

 vertebrte, wanting the ribs, were preserved in natural juxtaposition. A figure 

 of this unique specimen, discovered by S. H. Beccles, Esq., f.g.s., is, with 

 his kind permission, given in PI. 24 {Dinosauria). In a second portion of the 

 same nodule two almost entire and consecutive ribs of the right side were preserved : 

 a smaller fragment contained the bodies and neural arches of two consecutive 

 vertebree in natural junction from a more anterior part of the chest than the series of 

 the three vertebras. Two detached vertebrae, wanting the spinous process, from a 

 hinder portion of the trunk, had been obtained either from, or near to, the above- 

 described large nodule. 



The three vertebrae (PI. 24) retain, what is rarely preserved in such complex 

 parts of fossil Saurians, the entire neural spines, »«. and exhibit a disposition and 



