XXI. — On the Discoveri/ of an almost perfect Skeleton of the Plesiosaurus. 

 By the Rev. W. D. CONYBEARE, F.R.S. M.G.S. 



[Read February 20, 1824.] 



X AM highly gratified in being able to lay before the Society an account of 

 an almost perfect skeleton of Plesiosaurus *, a new fossil genus, which, from 

 the consideration of several fragments found only in a disjointed state, I felt 

 myself authorized to propound in the year 1821, and which I described in 

 the Geological Transactions for that and the following year. It is through 

 the kind liberality of its possessor, the Duke of Buckingham, that this spe- 

 cimen has been placed for a time at the disposal of my friend Professor 

 Buckland for the purpose of scientific investigation. 



At the period of my former communications it was natural and even just 

 that in the minds of many persons interested in such researches, much hesi- 

 tation should be felt in admitting the conclusions of an observer who was 

 avowedly inexperienced in comparative anatomy ; and there might have then 

 appeared reasonable ground for the suspicion that, like the painter in Horace, 

 I had been led to constitute a fictitious animal from the juxtaposition of in- 

 congruous members, referable in truth to different species. But the magni- 

 ficent specimen recently discovered at Lyme has confirmed the justice of my 

 former conclusions in every essential point connected with the organization 

 of the skeleton. 



The only material error which I have to correct relates to the bones which 

 I supposed to be the radius and ulna : but with regard to the other parts of 

 the skeleton, in assigning to the same animal the heads and vertebrae which 

 had at that time never been found in connexion, and whose actual relation 

 was therefore regarded by many as equivocal, in indicating the order and 

 place of the several kinds of vertebrae, and in tracing the osteology of the 

 humero-sternal parts, my opinions have received full confirmation. In the 

 attempted restoration of the paddle also (though professedly given only on 



* Some philological objections having been made to the composition of the word Plesiosaurus, I 

 beg to state that it is formed on the very same principle as the words \(rayyeXos, I<r6$eySpos, &c,, 

 all of approved classical use. 



