338 FOSSIL REMAINS OF LABYRINTHODON. [Ch. XXII. 



sioii are salient, in high relief, and afford models of the feet, toes, and claws 

 of the animals which trod on the clay. On the same surfaces Mr. J. Cun- 

 ningham discovered (1839) distinct casts of rain-drop markings. 



As neither in Germany nor in England any bones or teeth had. been 

 met with in the same identical strata as the footsteps, anatomists indulged, 

 for several years, in various conjectures respecting the mysterious animals 

 from which they might have been derived. Professor Kaup suggested 

 that the unknown quadruped might have been allied to the Marsupialia ; 

 for in the kangaroo the first toe of the fore foot is in a similar manner set 

 obliquely to the others, like a thumb, and the disproportion between the 

 fore and hind feet is also very great. But M. Link conceived that some 

 of the four species of animals of which the tracks had been found in 

 Saxony might have been gigantic Batrachians ; and Dr. Buckland desig- 

 nated some of the footsteps as those of a small web-footed animal, prob- 

 ably crocodilean. 



In the course of these discussions several naturalists of -Liverpool, in 

 their report on the Storton quarries, declared their opinion that each of 

 the thin seams of clay in which the sandstone casts were moulded had 

 formed successively a surface above water, over which the Cheirotkerium 

 and other animals walked, leaving impressions of their footsteps, and that 

 each layer had been afterwards submerged by a sinking down of the sur- 

 face, so that a new beach was formed at low water above the former, on 

 which other tracks were then made. The repeated occurrence of ripple- 

 marks at various heights and depths in the red sandstone of Cheshire had 

 been explained in the same manner. It was also remarked that impres- 

 sions 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 remains 

 discovered in the Trias, both of Germany and England, were carefully 

 examined by Prof. Owen. He found, after a microscopic investigation of 

 the teeth from the German sandstone called Keuper, and from the sand- 

 stone of Warwick and Leamington (fig. 437), that neither of them could 

 be referred to true saurians, although they had been named Masto- 

 donsaurus and Phytosaurus by Jager. It appeared that they were of 

 the Batrachian order, and attested the former ex- 

 istence of frogs of gigantic dimensions in compari- Fi s- ^ 

 son with any now living. Both the Continental 

 and English fossil teeth exhibited a most compli- 

 cated texture, differing from that previously ob- 

 served in any reptile, whether recent or extinct, but 



, • . , IT-,, « Tooth of Labyrinthodon; 



most nearly analogous to the Ichthyosaurus. A natsize. Warwick sand- 

 i section of one of these teeth exhibits 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 

 ■Lahyrintliodon for the new genus. The annexed representation (fig. 



