﻿GREAT OOLITE. 



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smooth, or unarmed, as in Cetacea and Enaliosauria. But, as will be shown in the con- 

 cluding subject of the present contribution to the History of British Fossil Reptiles, a new 

 interest will attach itself to the occurrence of an osseous spine, seemingly dermal, in 

 contiguity with the parts of the fore-limb which were wanting, or not discovered, in the 

 Kirtlington example of Cetiosaurus longus. 



In Scelidosaurus the number of vertebrae between the skull and sacrum is twenty- 

 three or twenty-four j 1 in Iguanodon the same region includes more than seventeen 

 vertebrae : in this genus there are five sacral vertebrae : in Scelidosaurus four. In no 

 Dinosaur has the number of caudal vertebras been so satisfactorily or approximately 

 demonstrated as in Scelidosaurus. Thirty-five of these vertebrae were obtained in con- 

 secutive articular association in the individual which forms the subject of the Monograph 

 above cited. If we allow the Cetiosaur, on this analogy, twenty-four vertebrae between 

 the skull and sacrum, averaging 5 inches each in length, and add an inch for the inter- 

 vertebral connective tissues, we get a total length of trunk at 12 feet. Four sacral 

 vertebrae would add two feet. Taking the number of the caudal vertebrae at that shown 

 in Scelidosaurus, and the reduction of length in the ten terminal ones not to be more 

 than is shown in Tab. IX, fig. 2, of the Monograph quoted, the length of the tail of 

 Celiosaurus longus may be set down at 17 feet. Thus we get an approximative idea of 

 the length of this Cetiosaur, minus the head, as 31 feet. The fortunate discovery of the 

 skull or lower jaw, or a mandibular ramus, would supply the ground for completing an 

 idea of the size of the whole animal. As the second femur of Cetiosaurus longus in the 

 Enslow locality exceeded in size the first, so it may ultimately prove not to represent the 

 extreme size attained by individuals of the species ; and the length of 7 inches shown by 

 the typical caudals would found an estimate of 35 or 36 feet for the length of trunk and 

 tail of Cetiosaurus longus. 



As evidences of this species have now reached me from four counties — Yorkshire, 

 Northamptonshire, Buckinghamshire, and Oxfordshire — I submit that there is no case, 

 according to the 'canons of zoological and botanical nomenclature' adopted by the 

 ' British Association for the Advancement of Science,' 3 for suppressing the original name 

 proposed by the discoverer of the species, and substituting one which is in some degree 

 misguiding. I would also plead for a retention of the orthography of the generic name. 3 



1 Monogr. cit., p. 1 1 . 



2 'Report,' &c, for the year 1842. 



3 In framing this name the diphthong in ki'itcios was dropped, as in ' pliocene,' ' miocene,' &c. 



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