226 FOSSIL REPTILES. 



last of these four, which is the sixteenth. But it is difficult 

 to say if it has not been displaced, and it might easily be be- 

 lieved that it was originally behind the fifth of those vertebrae 

 with large transverse apophyses, which would then be the 

 lumbar vertebrae. Then come twelve traces which might have 

 been the marks of the bones formed like a V, placed under the 

 vertebrae of the tail. 



On the sides are two bones which Stukely took for femora ; 

 but by their form they might be judged to be ossa ischia, tole- 

 rably like those of the crocodile. There are besides, on the left 

 side, two short and broad impressions, which might have been 

 the top of the tibia and peroneum. 



The plesiosauri and ichthyosauri have long bones much 

 resembling the ischia just mentioned ; and, on the whole, M. 

 Cuvier is of opinion that the specimen in question is as likely 

 to belong to either of these new genera as to the crocodile. 

 Our respected countryman, Mr. Conybeare, has decided that 

 it does belong to the plesiosaurus. 



The other specimen was found on the sea-coast, near Whitby, 

 in Yorkshire, in a blackish slate, called aluminous rock, and 

 which comes off in exfoliations. Ammonites are observable in 

 it, the interior of which is filled with spathic concretions. 



As the flood tide used to cover this skeleton with five or six 

 feet of water, it was considerably damaged by the sand and 

 pebbles cast upon it. As it was at no great distance from a 

 steep shore, very much elevated, and which the sea is inces- 

 santly undermining, there is no doubt but that it was formerly 

 covered by the entire of this cliff. When a drawing of it was 

 taken, a part of the vertebrae, and the slenderest bones of the 

 head, had already been washed away by the sea, or carried oflf 

 by virtuosi. 



The spinal column was nine feet long, but probably not 

 complete. There was also a head a little displaced, two feet 

 nine inches in length. 



But twelve vertebrae of the tail remained in their place, and 



