176 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. III. 



fossil thus labelled consists of the cranium and part of the 

 vertebral column, with many ribs, of a small saurian reptile, 

 from the Lias at Boll, which has been referred to a distinct 

 genus by H. von Meyer. I have not been able to obtain 

 any further information respecting this specimen. 



Crocodilus toliapicus. Wall-Case B. [2.] The discovery 

 of the cranium of this species in the London clay of the Isle 

 of Sheppey described by Baron Cuvier, afforded the first 

 certain proof of the existence of a true crocodile in the eocene 

 deposits of England. The specimen in the Case before us is 

 remarkably fine : it is above two feet long, and both jaws 

 and teeth are in a beautiful state of preservation. The 

 recent Crocodilus acutus of the West Indies is stated to 

 be the nearest living representative of this ancient tertiary 

 species. 



Crocodilus Spenceri. Wall-Case B. A remarkably fine 

 skull of a crocodile, two feet in length, and ten inches in 

 width, from the Isle of Sheppey, is placed on the ledge near 

 the specimen -last described ; a cranium of this species is 

 figured in Dr. Buckland's " Bridgewater Essay," PI. XXV. '; 

 and described in " Brit. Assoc. Report," p. 65. 



Professor Owen states that the most characteristic diffe- 

 rences which this species presents in comparison with the 

 Crocodilus biporcatus, or other existing species of Crocodile 

 or Alligator, are the larger size of the temporal holes, as com- 

 pared with the orbits, the more regular and rapid diminution 

 of the head towards the snout, the straight line of the alveolar 

 tract, and the greater relative length and slenderness of the 

 muzzle. It most nearly resembles the Bornean species (Croc. 



Eemains of this Crocodilian reptile have been obtained 

 from the London clay at Bracklesham, on the Sussex coast ; 

 and I have collected several vertebrae, dermal bones, teeth, 

 and portions of the cranium, from the eocene strata near 

 Lymington. 2 



In Mr. Dixon's collection there was a chain of eight ver- 

 tebrae, including the sacral and biconvex first caudal, which is 



1 For details consult "Brit. Assoc. Report," (1841), pp. 66, 67. 



2 " Geological Excursions round the Isle of Wight, and along the 

 aijacent coast of Hampshire/' p. 163. 



