122 THE MICROSCOPE. 



identity of the Keuper Sandstein of Wirtemburg, with 

 the New Red Sandstone of Warwickshire, has been 

 satisfactorily demonstrated by means of the micro- 

 scope. Some years ago, Professor Jaeger found in 

 the German Keuper formation some remarkable fossil 

 teeth, which were of great size, conical or canine in 

 form, and distinctly striated. In 1840 Professor 

 Owen found similar teeth in the New Red Sandstone 

 of Coton End quarry, Warwickshire. What was the 

 nature of the animal to which these teeth belonged ? 

 From external characters it had at first been inferred 

 that the teeth were those of some Saurian reptile ; but 

 the results of a microscopic examination of the teeth, 

 both from the German Keuper and the New Red Sand- 

 stone of Warwickshire, revealed a very remarkable 

 and complicated structure; hence, provisionally, the 

 creature to which the teeth were supposed to belong 

 was named Labyrinthodon, by Professor Owen ; but 

 this peculiar internal structure of the tooth a structure 

 formed by "the convergence of numerous inflected 

 folds of the external layer of cement towards the 

 pulp cavity" is typically presented also in the teeth 

 of fish-lizards and lizard-like fish ; hence it might be 

 reasonably inferred that the labyrinthodon would 

 combine with its reptilian characters an affinity with 

 fish. The subsequent discovery of some of the bones 

 of the labyrinthodon, as the vertebrae, jaws, hume- 

 rus, femur, and toes, &c., have gone far to establish 

 this inference ; and there is much reason to believe 

 that that strange creature, the labyrinthodon, was a 

 gigantic frog-like animal five or six feet long, with a 

 mixture of fish and crocodilian characters, and that in 

 all probability it was identical with the animal whose 

 footprints have been discovered in the quarries of the 

 grey quartzose and red sandstone of Saxony, and in 

 the sandstone quarries of Stourton, in Cheshire. 



