OOLITIC DINOSAURS. 581 



Shortly after I was able to differentiate certain saurian vertebrae from those ascribed 

 to the genera Iguanodon, Hylceosaurus, Megahsaurus, and Poikilopleuron, not only by 

 superiority of size, but by differences in form, proportions, and structure.* The latter 

 character applied, more especially, to these huge unknown fossil bones in the comparison 

 with PoikilojiIeHron , in the vertebrae of which four-footed reptile ossification is incom- 

 plete and large chondrosal vacuities are left in the substance of the centrum, which, in 

 the fossils, become filled with spar.f 



From the similarity of texture of the vertebrae of the new genus of Saurian 

 so indicated to that in the limb-bone from " Blechingdon,'' Enslow, I suggested that it 

 might belong to Cetiosaurus.X The cetaceous hypothesis of the huge Oolitic Vertebrate 

 was thereupon abandoned, and my determination was adopted in the second edition of the 

 ' Bridgewater Treatise,' and also by Lyell, who gives a reduced cut of the fossil in his 

 ' Manual of Geology,' ch. xx. 



In 1848 Dr. Buckland informed me of the discovery of a femur, 4 feet 

 3 inches in length, which, from the correspondence of its texture with that of the 

 metatarsal from Blechingdon, and also with that of some fragmentary long bones from 

 Blisworth, Northamptonshire, I referred to the genus Cefiosaiirus, and to the species 

 from the Great Oolite called Cetiosaurus longus. % 



More recently (1868 — 70) a considerable proportion of the skeleton was discovered 

 in the quarries of the Great Oolite of Enslow Rocks at Kirtlington Station, eight miles 

 north of Oxford, the bones of which more nearly approached in size to the type 

 specimen of Cetiosaurus longus.\ I, therefore, visited Oxford for the purpose of studying 

 these remains. 



Such of the trunk-vertebrae as were sufficiently entire appeared to have come from 

 the fore part of that region, and showed the opisthocoelian character of those vertebrae 

 as in certain Dinosaurs. 



In the best preserved anterior dorsal vertebra the parapophysis, short but large in 

 vertical extent, shows remains of the articular surface for the head of the rib. The 

 diapophysis, supported by a strong buttress-like ridge, is directed upward and outward 

 at an angle of 45° with the neural spine. The distance between the articular surface for 



of each bind foot of a Cetiusaurus, wherewitb he was able to compare the above fossil long bone, "incom- 

 plete at both extremities," considers the determiualiou of it as a metatarsal of large size to be 'probably 

 true.'—' Geology of Oxford,' &c., 8vo, 1871, p. 285. 



* ' Proceedings of the Geological Society of London,' June, 1811, loc. cit. 



t The chief of these cavities, being in the centre of the vertebrse, was termed 'medullary' (loc. cit., 

 p. 4.'39) ; but I have since had reason to conclude that it was occupied in the living Saurian by unossified 

 chondrine. 



X 'Report,' ut supra, p. 101. 



§ lb., ib. Also a?ite, p. 413. 



II "Vertebrse 8, 9, and 11 inches in diameter," " monstrous ribs," " femora upwards of 5 feet iu 

 length." — 'Athenaum,' April 2nd, 1870. 



