Professor H. G. Seeley — Dinosaurs from Rhcetic Beds. 5 



anything seen in British carnivorous saurians, and is especially 

 large as compared with the dorsal vertebrge of Megalosaurus, in 

 which the vertebras are as unlike the fossil as are the limb-bones. 



The large dorsal vertebra of Avalonia Sanfordi is somewhat crushed, 

 and has the body of the centrum unusually constricted, both at the 

 sides and the base. Above the middle of the side, and a little behind 

 the middle length, is a concave impression, pinching the sides till 

 they are about 3 inches apart. The flattened anterior face is not 

 well preserved, and the margin of the deeply concave posterior face 

 is rounded. The measurements indicate a moderate arching of the 

 back. The neural canal is 2-1% inches high in front and 2 inches 

 wide ; behind it is wider than high. 



The neural arch has a strong elevated capitular facet 2 inches deep 

 and 1-^ inch wide, vertical and flat, with the anterior border straight 

 and the posterior border convex. It is an elevation upon and ex- 

 pansion of the anterior buttress of the arch, just as the tubercular 

 facet (which is lost with the transverse process) is supported by the 

 posterior buttress, which is a narrow oblique ridge. Hence there is 

 a concavity between the facet and the ridge, which extends under 

 the transverse process. The large posterior zygapophyses extend 

 back beyond the neural spine ; and the buttresses below them, which 

 face obliquely outward and backward, are excavated for the reception 

 of the pre-zygapophyses. The neural spine is comjDressed and vertical, 

 about 3 inches from back to front and half an inch thick, though 

 there is no certain indication of its height. The transverse width 

 over the neural arch as indicated was ten inches. The height of the 

 vertebree up to the summit of the neural spine may have been 

 20 inches. The transverse elevation of the capitular facet an inch 

 above the base of the neural arch is a remarkable and distinctive 

 character. The large size of the vertebra is somewhat Cetiosaurian. 



The ribs were strong : one fragment, more than 15 inches long, is 

 3 inches deep at the fracture towards the proximal end, where the 

 external surface is reflected somewhat backward, and as the rib 

 extends outward its plane becomes twisted, so as to present a wider 

 and oblique lateral superior surface, the measurement being about 

 1| inch at the fracture at the distal end. 



The remainder of the vertebrge are referred to Picrodon Herveyi. 

 They comprise dorsal vertebrge, with the body of the vertebrse com- 

 pressed from side to side, and relatively more elongated, but with 

 the front of the centrum narrower than the back. There is a distinct 

 suture between the neural arch and the centrum. And the neural 

 arch has strong upwardly converging buttresses, supporting the 

 transverse processes. The articular faces are deeper than wide ; the 

 width does not exceed 4^ inches. 



A caudal vertebra, showing the base of the transverse process, has 

 the centrum about 5 inches long, and the base of the transverse 

 process 2^ inches from front to back, by 1^ inch deep. The articular 

 face is about 5 inches deep, by less than 4 inches wide, but the 

 preservation does not show whether chevron bones were developed 

 at the hinder border. A later caudal, with the articular surface 



