Mr. De la Beche on the South Coast of England. 43 



portunity is afforded for the examination of its fossils^ and many have recently 

 been brought to light which were before unknown : the most remarkable 

 of these are the remains of a singular animal, which has been named Ichthyo- 

 saurus by Mr. Konig, from its being supposed to form a link between the 

 Saurians and Pish. Sir Everard Home gives it the name of Proteosaurus, 

 and has described several parts of its osteology in the Philosophical Transac- 

 tions*; and the Rev. W. D. Conybeare and myself have published some fur- 

 ther account of it in the fifth volume of the Transactions of this Society. 



The remains of this animal are by no means rare ; they are principally dis- 

 covered at Black Ven, and most commonly in the slaty or marly part of the lias. 

 Three species of this fossil genus appear to me very distinguishable ; the 

 principal differences consisting in the form of the skull and teeth. I shall 

 content myself at present by giving the names, communis, platyodon, and 

 tenuirostris, to three species hitherto discovered ; reserving for a future 

 communication by the Rev. W. D. Conybeare and myself the reasons for so 

 naming them, as well as a detailed account of the differences in their teeth. 



Some of the animals of the genus Ichthyosaurus must have been of an enor- 

 mous size. I have in my possession a vertebra of one of them, which mea- 

 sures seven inches and three quarters in diameter, with various portions of 

 the paddle, which, when entire, must have measured (including the humerus) 

 at least two feet and a half in length f. 



Besides the remains of the Ichthyosaurus, there are found in the lias of Lyme 

 the bones of another animal, the Plesiosaurus, described by the Rev. W. D. 

 Conybeare and myself in the fifth volume of the Geological Transactions. 



There occur also in the lias at this place singular bodies, which appear to 

 have been the external defensive radii of some fish, and to have been used in 

 the same manner with similar bones of the Balistes tribe. Their shape will be 

 seen by a reference to Plate IV. figs. 1 and 2. They are longitudinally grooved 

 from the apex P to C, which appears to have been the part that protruded out 

 of the body of the fish ; and from C to D, the part imbedded in the body, the 

 bone is hollow, as will be seen by the section of fig. 1 at b, represented fig. 3. 

 This bone is armed from the apex P to a, figs. 1 and 2, with teeth-like bony 

 processes in two rows, placed so as to give a zigzag appearance. I possess 

 specimens in which several of these bones are placed side by side; and it 



* See several papers io the Philosophical Transactions, by Sir E. Home, witli the reasons 

 for naming it Proteosauriis. — Vols. civ. p. .571; cvi. p. 318 ; cviii. p. 24 ; cix. pp.209 — 212; 

 ex. p. 159. 



+ Remains of the Ichthyosaurus are found in the lias, at Watchet, Somerset ; at Bath ; at (he 

 Old Passage, Gloucestershire ; and at Whitby in Yorkshire. 



g2 



