36 FOSSIL REPTILIA OF THE 



individuals of the same species of Saurian." Subsequent experience of this constancy 

 in the dorso-lumbar and caudal regions of the spine in Crocodilia and Dinosuunn 

 has confirmed me in that opinion. But I expressly stated, when proposing the 

 specific names of the different species of Cetiosaurus, that those names referred 

 " to the relative length of their vertebrae."* The highest authorities in palaeontology 

 had sanctioned this system of naming species from characters of instructive parts. 

 And no naturalist appears to have supposed that the Falceotherium latum of Cuvier 

 had necessarily a trunk as broad in proportion as the foot, or that the whole frame of 

 Anoplotherium obliquum was askew. The Raia spiralis of Miinster was not a twisted 

 Skate, any more than the Otodus ramosus of Agassiz was a branched Shark. As 

 to the plea of preventing confusion by changing the published name of an adequately 

 defined species, competent naturalists concur in denouncing the practice, as being the 

 chief cause of the present grievous confusion in zoological synonymy. 



The objections to the species Cetiosaurus brevis, and a subsequent attempt to 

 suppress the genus, call for notice here on account of their admission into volumes of 

 so high a scientific repute as the ' Transactions of the Royal Society.' The reporters 

 on the papers by Drs. Melville and Mantell must have assigned some value to 

 the remarks which here receive the explanation from the author against whom 

 they were directed. 



Genus — Pelorosaurus, Mantell. Tab. XI, XII. 



When publishing condensed descriptions of the previously undescribed, and 

 for the most part undetermined, fossil remains of Reptilia, in my 'Reports' on 

 that class submitted to the British Association in 1840 and 1841, it was known 

 that the drawings made by aid of the grant voted for that purpose by the Association 

 would subsequently be published in the work or monographs containing the more 

 complete history of those British Fossil Reptiles. Reduced figures of the vertebrae, 

 ascribed to Cetiosaurus brevis, and described in pp. 95 — 100 of the 'Report' of 1841, 

 were, however, published, by anticipation, in the ' Philosophical Transactions ' for 

 1850; the author quoting a remark by Sir J. G. Dalyell, that "delineation should 

 be the inseparable accompaniment of description in natural history" (tom. cit., 

 p. 382), and citing the descriptions in detail of these vertebras, given "by Dr. 

 Melville, in the ' Philosophical Transactions,' 1849, p. 296." 



* Report, 'Trans. Brit. Assoc.,' 1841, p. 102. 



