ANCIENT SALAMANDERS 97 



it to the batrachian type with permanent gills. Both tend to 

 show the artificial nature of the arrangement by which, under 

 most systems of classification, fishes are separated by a wide gap 

 from reptiles and amphibians. 



The Labyrinthodonts ranged through three geological periods 

 the Carboniferous, the Permian, and the Triassic. At the 

 time when the coal-forests of Europe and America were flourish- 

 ing, they were tenanted by a large number of Labyrinthodonts. 

 These, and others of the succeeding Permian period, which may 

 conveniently be taken together, have been specially studied by 

 such authorities as Professors Huxley and Cope, Dr. Fritsch, 



FIG. 18. Skull of Archegosaurus. (Permian.) 



Professor Miall, and others. The limits of space will only 

 allow us to make a small selection from the numerous forms 

 described by them. 



Cricotus is an American genus described by Professor Cope, 

 from the Permian strata of Texas. The skull and some of the 

 scales belonging to the under surface of the body are shown in 

 Fig. 19. The Eryops, of which the skull is shown in the same 

 figure, is considered by Professor Seeley to belong to a higher, 

 though related group, the Anomodonts (Chap. VII.). The one 

 group is much connected with the other, and the question of the 



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