80 Rev. George Young on a Fossil Crocodile discovered 
taken on the spot ; but I have now no doubt that they were part 
of its scales. It corresponded with the present specimen, both 
in the shape of the head, and in the form and number of the 
vertebras; and it was also about the same size, being 15 feet 
long. 
Within these few years, other genuine relics of the crocodile 
have been discovered near Whitby, consisting of detached heads, 
portions of the vertebral column, &c. ; but they have been usual- 
ly assigned to that new fossil animal the Plesiosaurus. The re- 
cent discovery has enabled us to correct this mistake, indepen- 
dent of the more full account of the Plesiosaurus, lately published 
in the Geological Transactions. 
The Whitby alum-shale, however, contains undoubted re- 
mains of the Plesiosaurus. There are fin-bones, vertebrae, &c. of 
that animal in the Whitby Museum ; and, prior to the discovery 
of the Plesiosaurus dolichodeirus, figured in the Geological 
Transactions, vok i. 2d series, pi. xlviii., we had specimens 
which convinced us that Mr Conybeare had been mistaken in 
his attempt to restore the fin of that animal, as figured in the 
Geological Transactions, vol. v. pi. 42. . It would be an im- 
portant object to procure a good specimen of the whole ani- 
mal. Such a discovery might enable us to ascertain whether 
the unnatural length of neck, which it appears to have in the 
specimen of 1828, really belongs to it, or is only the result of 
accidents, which have violently displaced and altered the greater 
part of its bones. Our Plesiosauri, if not of different species, 
must have been of very different sizes. One specimen of the 
fin-bones of that animal, in the Whitby Museum, must have 
belonged to a specimen of great bulk, as the first row of oblong 
pieces in the phalanges of the fin are 3 inches long each. 
Of the Ichthyosaurus, three or four species occur in our alum- 
shale. The Ichth . communis of Mr Conybeare is most fre- 
quently met with. The fine specimens, published in the Geo- 
logical Survey, PI. xv. fig. 1 and 2, and now in the Whitby 
Museum, are of this species. The specimen. No. 3. of the same 
plate, described and figured in the Memoirs of the Wernerian 
Society, vol. iii., is perhaps of another species, the head being 
somewhat differently shaped, and the snout (which is imperfect) 
having apparently been longer in proportion to the size of the 
