748 PROP. OWEN ON THE AFFINITIES OF THE MOSASAUR1DJE. 



41. On the Affinities of the Mosasaurid^;, Gervais, as exemplified 

 in the Bony Structure of the Fore Pin. By Prof. Owen, C.B. 

 F.R.S., F.G.S., &c. 



In the year 1848 Professor Henry Rogers submitted to me a series 

 of fossil remains which he had discovered in a Greensand deposit in 

 New Jersey, United States. The results of my examination were 

 communicated to the Geological Society, January 31, 1849*. The 

 paper was sent, in due course, to Referees for a ' Report,' but was 

 lost. 



Fortunately the President, Sir II. T. De La Beche, had made notes 

 of the chief conclusions communicated and discussed on the 31st of 

 January, and referred to them in his "Anniversary Address" de- 

 livered February 16, 1849 1. To these brief notices I added, at the 

 request of the Council, some observations on the characters of the 

 skull and vertebras deduced from the fossils, which I referred to the 

 genus Mosasaurus ; and, in reference to the metacarpal or metatarsal 

 and phalangeal bones of the same genus, I quoted the President's 

 note, " that they indicated the extremities of the great Saurian to 

 have been organized according to the type of the existing Lacertilia, 

 and not of the Enaliosauria, or marine lizards "J. 



Of the natatory character of the limb to which these metacarpal 

 and phalangeal bones belonged, there was no question. The ques- 

 tion was, to what type of natatory extremity that of the Mosasaurus 

 should be referred ? Cuvier had recorded his conclusion that the 

 fins of the Mosasaur were more or less like those of the Delphinidce 

 or of the Plesiosauri §. 



Subsequently, in my ' Monograph on the Fossil Reptiles of the 

 Cretaceous Formations' ||, referring the genus Mosasaurus to a tribe 

 Natantia (p. 29), of the order Lacertilia (p. 19), I stated with regard 

 to the phalangeal bones, that " they indicate the extremities of that 

 gigantic Lizard to have been organized according to the type of the 

 existing Lacertilia, and not of the Enaliosauria or Cetacea " (p. 40). 



The value of such conclusion from the few materials then at my 

 command could only be estimated by comparison with a more com- 

 plete specimen of a Mosasaurian fin ; and such has been obtained by 

 the able and indefatigable palasontologist, Prof. 0. C. Marsh, who has 

 given a description and figure of the specimen in his memoir " On 

 the Structure of the Skull a"nd Limbs in Mosasauroid Reptiles," in 

 the ' American Journal of Science and Arts,' vol. iii. June 1872. 



* Quarterly Journal of the Geological Society of London, vol. v. p. 380. 



t lb. p.xliii. $ lb. p. 382. 



§ " Les os des mains et des pieds, autant qu'on les connoit, sembleroient au 

 contraire avoir appartenu a des especes de nageoires assez contractees, et plus 

 ou moins semblables a celles des dauphins ou des plesiosaurus." — Ossein. Foss. 

 4to, 1829, t. v. 2de partie, p. 336. 



|| Part I., in Volume of the Palaeontographical Society, issued in 1851. 



