580 BRITISH FOSSIL REPTILES. 



portion of the skull, not one tooth, had been discovered so associated with Cetiosaurian 

 bones, at the date of my " Reports on British Fossil Reptiles,"* as to throw any additional 

 light on the ordinal affinities of the new genus. I had not, then, grounds for dissociating 

 it from the Crocodilian group or order. The grand accession of evidences of the osseous 

 framework of one of the speciesf added to the original Collection of Buckland, preserved 

 ill his Museum at Oxford, by his eminent successor. Professor Phillips, F.R.S., by 

 whom they have been instructively elucidated in his excellent work on the ' Geology of 

 Oxford,'! lias proportionally advanced the means of determining the ordinal relations and 

 affinities of the genus. The inferences which may be drawn in favour of the Dinosaurian 

 characters of the sacrum will be subsequently discussed. But the demonstration of the 

 sacral characters of the more recently discovered Cetiosauroid genus Omosaurus adds 

 to the grounds for referring the type-species of Cetiosaur to the Dinosaurian group of 

 Reptilia. 



It is characteristic of the accidents that attend the quest and acquisition of the 

 remains of extinct Vertebrates, that skull, jaws, and teeth should have escaped the careful 

 operations to which we are indebted for the present means of restoring both Cetiosaurus 

 hngus and Omosaurus armatus. Of the former reptile a single doubtful and mutilated 

 tooth was all that Prof. Phillips could refer with any degree of probability to that 

 species. 



That the side-pits of saurian vertebrae have no essential relation to largely cancellated, 

 pseudo-pneumatic structure of the bones is shown by their presence in the anterior 

 trunk-vertebra3 of the genus for which the uniformly close though coarse osseous textm-e, 

 as in the whale tribe, suggested the generic name Cetiosaurus. 



The first indication of this type of Saurian was, however, afforded by an inspection 

 of a limb-bone, submitted to me by Dr. Buckland in 1838, when I was engaged in 

 collecting materials for my ' Report ' to the British Association " On the Fossil Reptilia 

 of Great Britain." Buckland had referred to this fossil in his ' Bridgewater Treatise,' 

 1st edit., 1836, in the following terms: — "There is in the Oxford Museum an ulna 

 from the Great Oolite of Enstone " (Enslow probably meant), " near Woodstock, Oxon., 

 which was examined by Cuvier and pronounced to be cetaceous ; and also a portion of 

 a very large rib, apparently of a whale, from the same locality." 



This limb-bone I could not match with any then known to me in the Cetaceous order. 

 Yet, save a thin compact outer crust, the osseous structure was, where exposed, like that 

 in the humerus of a "Whale or Grampus ; there was no medullary cavity. In shape the 

 resemblance, though remote, seemed nearest to that of the outer metatarsal of a 

 Monitor Lizard. § 



* ' Reports of the British Association for the Advancement ofScience ' for the years 1839 and 1841. 



t " Cetiosaurus longus," lb., ' Report ' of 1841, p. 101 ; ante, p. 413. 



X 8vo, 1871. 



§ Prof. Phillips, who had obtained, in 18"0, from the Great Oolite at Enslow, the three metatarsals 



