Cn. xxn.] 



FOSSIL REMAINS OF LABYRINTHODON. 



445 



was also remarked that impressions of such depth and clearness could 

 only have been made by animals walking on the land, as their weight 

 would have been insufficient to make them sink so deeply in yielding 

 clay under water. They must, therefore, have been air-breathers. 



When the inquiry had been brought to this point, the reptilian re- 

 mains discovered in the Trias, both of Germany and England, were care- 

 fully examined by Prof. Owen. He found, after a microscopic investiga- 

 tion of thte teeth from the German sandstone called Keuper, and from 

 the sandstone of Warwick and Leamington (fig. 485), that neither of 

 them could be referred to true saurians, although they had been named 

 Mastodonsaurus and Phytosaurus by Jager. It 

 appeared that they were of the Batrachian order, 

 and of gigantic dimensions in comparison with any 

 representatives of that order now living. Both 

 the Continental and English fossil teeth exhibited 

 a most complicated texture, differing from that 

 previously observed in any reptile, whether recent 

 or extinct, but most nearly analogous to the Ich- 

 thyosaiwus. A section of one of these teeth ex- 

 hibits a series of irregular folds, resembling the 

 labyrinthic windings of the surface of the brain ; and from this 

 character Prof. Owen has proposed the name Ldbyrinthodon for the 

 new genus. The annexed representation (fig. 486) of part of one is 



Fig. 485. 



Tooth of Ldbyrintho- 

 don; nat. size. War- 

 wick sandstone. 



Pig. 486. 



Transverse section of tooth of Ldbyrinthodon Jaegeri, Owen {Mastodonsaurus Jaegeri, 



Meyer) ; nat. size, and a segment magnified. 



a. Pulp cavity, from which the processes of pulp and dentine radiate. 



given from his " Odontography," plate 64 A. The entire length of 

 this tooth is supposed to have been about three inches and a half, and 

 the breadth at the base one inch and a half. 



