ON BRITISH FOSSIL REPTILES. 101 



quently discovered and in the collection of Mr. Kingdon, that the characters 

 of the Cetiosaurus were first determined*. They include a portion of the 

 tail consisting of ten vertebrae ; the anterior and larger ones were five inches 

 and a half in length, seven inches across the articular surface at each end of 

 the body, and not less than two feet in vertical diameter, including the neural 

 (superior) and haemal (inferior) spines. Both articular extremities are con- 

 cave, the anterior one being rather the deepest; but the difference is less 

 than in the Cetiosaurus brevis. The articular cavities become shallower in 

 the posterior caudal vertebrae ; these gradually diminish in transverse and 

 vertical diameter, but retain the same length, even %vhen they are reduced to 

 two inches and one inch and a half in breadth. The body of the vertebra 

 has no central cavity, in which respect the present, like the preceding species 

 of Cetiosaurus, may be distinguished from the Poikilopleuro7i, where such 

 cavity exists. The neurapophysis does not equal in antero-posterior extent 

 the centrum or body of the vertebra, the disparity increasing in the posterior 

 caudal vertebras : the arch is placed towards the anterior end of the vertebra. 

 The hsemapophysial arch has a less contracted base than in the Igaanodon,, 

 and the proximal extremities of the haemapophyses are free, as in the Cetio- 

 saurus brevis. 



One of the ungual phalanges, which is conical, snbcompressed, and slightly 

 curved, is traversed on each side by the usual vascular groove, curved with 

 the convexity upwards, measuring five inches in length, and three and a half 

 across its articular base. The bone alluded to in Buckland's ' Bridgewater 

 Treatise,' vol. i. p. 115, and figured in Mr. Lyell's ' Elements of Geology' 

 (1838), p. 384-, is a metatarsal of the Cetiosaurus. This fossil was found in 

 the great oolite of Enstone, near Woodstock. 



A few large caudal vertebrae, and other bones of the Cetiosaurus, have been 

 discovered in the oolite of the neighbourhood of the town of Buckingham, 

 and form part of Dr. Buckland's museum. 



Some vertebrae, an entosternal bone, a coracoid, scapula, and fragments of 

 long bones, belonging apparently to the same skeleton, were disinterred from 

 the middle oolite during the railway cuttings near Blisworth, and are pre- 

 served in the collection of Miss Baker at Northampton. The anterior trans- 

 verse branch of the entosternum measures upwards of four feet across. The 

 posterior caudal vertebree, which, like those from Chipping Norton, measure 

 five inches and a half in length, have a more hexagonal form, resembling, 

 in this respect, the terminal caudal vertebrae of the Cetiosaurus brevis of the 

 Wealden ; they are, however, like the Chipping Norton specimens, of greater 

 length. 



In the museum of Professor Sedgwick, there is a caudal vertebra of the 

 Cetiosaurus from the neighbourhood of Stratford-on-Avon. The size of the 

 fossils hitherto obtained of the Cetiosaurus medius, especially the vertebrae, 

 if calculated according to the numbers and proportions of those of the Cro- 

 codiles, gives a length of forty feet to this species. 



Cetiosaurus longus. — In Professor Buckland's museum are preserved some 

 fossil remains, principally vertebrte, of another enormous Saurian, which 

 the form and texture of the vertebrae prove to belong to the genus Cetio- 

 saurus, but which differ in the proportions of the vertebras. One of these 

 — a caudal vertebra — from the Portland stone at Garsington, near Oxford, 

 measures in antero-posterior diameter of the centrum seven inches ; in trans- 

 verse diameter, seven inches nine lines ; in vertical diameter of the centrum, 

 six inches. Both articular extremities of the vertebra are slightly concave ; 

 the body is slightly compressed laterally ; its middle part gives a subquadrate 

 * See ProceecUugs of tlie Geological Society, June ISll. 



