THE TRIASSIC PERIOD. 



223 



surface of the body was protected by an armor of bony plates. 

 Some of the Triassic Labyrinthodonts must have attained 

 dimensions utterly unapproached amongst existing Amphibians, 

 the skull of Labyrinthodon Jcegeri (fig. 150) being upwards of 

 three feet in length and two feet in breadth. Restorations of 

 some of these extraordinary creatures have been attempted in 

 the guise of colossal Frogs ; but they must in reality have more 

 closely resembled huge Newts. 



Remains of Reptiles are very abundant in Triassic deposits, 

 and belong to very varied types. The most marked feature, 

 in fact, connected with the Vertebrate fauna of the Trias, and 

 of the Secondary rocks in general, is the great abundance of 

 Reptilian life. Hence the Secondary period is often spoken 

 of as the " Age of Reptiles. " Many of the Triassic reptiles 

 depart widely in their structure from any with which we are 

 acquainted as existing on the earth at the present day, and it is 

 only possible here to briefly note some of the more important 

 of these ancient forms. Amongst the group of the Lizards 

 (Lacertilia}, represented by Protorosaurus in the older Permian 

 strata, three types more or less certainly referable to this order 

 may be mentioned. One of these is a small reptile which 



Fig. 149. Section of the tooth of Labyrinthodon 

 (Mastodonsaurua) Jageri, showing the microscopic 

 structure. Greatly enlarged. Triaa. 



Fig. 150. a, Skull of La- 

 byrinthodon Jcegeri, much 

 reduced in size ; b, Tooth 

 of the same, Trias, Wurt- 

 tembergr. 



was found many years ago in sandstones near Elgin, in Scot- 

 land, and which excited special interest at the time in conse- 

 quence of the fact that the strata in question were believed to 



