NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 151 



Whether there was as complete an isolation in the earlier stages, repre- 

 sented perhaps by the New Mexican fauna, the author is less certain. The 

 similarity of the Poliosaiiridce to the Protcrosanria is so striking that a com- 

 munity of European and North American forms is suggested in the lowest 

 Permo-Carboniferous or late Pennsylvanian. Edaphosaurus crediierl is dis- 

 tinguished by Jaekcl from later forms by the sparse projections upon the 

 spines, a character also noticeable in Edaphosaurus novomexicanus from the 

 New Mexican beds. 



There are three possibilities of a connection between North America and 

 the other continents: Either with the Europe-Asia continent by way of the 

 North Atlantic continent ; to the south with Gondwana land by way of a land- 

 mass where Central America now lies; or across the Bering Straits with Asia. 



The possible connection with Europe-Asia will be first considered. Suess, 

 Freeh, De Lapparent, Netimeyer, and others have demonstrated the presence 

 of a great east-west chain of folded mountains across France and Germany, 

 reaching into southern England, Wales, and Ireland, which was uplifted in 

 Carboniferous time, and again viplifted after profound degradation in Per- 

 mian time. This is the great Hercynian chain, or Paleozoic Alps, composed 

 of an eastern, Variscan, portion in Germany and southern Russia, and a 

 western, Armorican, portion in France and Great Britain. The western ends 

 of the Armorican folds end abruptly at the Atlantic borders, or disappear 

 beneath it. On the opposite side of the Atlantic similar folds appear in New- 

 foundland, with equal abruptness, and are correlated with the Appalachian 

 folds to the south. The sudden ending of the folds in a rias coast is accepted 

 as evidence of their previous continuity across the ocean in the old North 

 Atlantic continent which probably disappeared in the great movements of 

 the Mesozoic. 



The presence of a great North Atlantic continent in Carboniferous and 

 earlier times is accepted as a proved fact by all the writers upon the subject, 

 and need not be defended here. The reader will find discussions of the sub- 

 ject by the following authors : 



De Latmay, La Science Geologique (chap, xii, p. 500), speaking of the 

 Stephanien, says: 



"Enfin, aux Etats-Unis, des accumulations de vegetaux se font egalement sur 

 des cotes a I'Ouest des Appalaches dans rillinois, I'Arkansas, le Kansas; une chaine, 

 homologue de la chaine hercynienne et qui la prolonge peut-etre, au Nord de notre 

 Mer Interieure, au Sud de notre grand sillon houiller, surgit dans les Appalaches." 



On a map opposite page 498 De Launay gives his idea of the paleography 

 of Westphalien time. In this he shows a land-mass occupying the whole 

 North Atlantic area, and connecting Europe with North America. 



In a map at the end of the book he shows the northern hemisphere, with 

 indications of the Hercynian folds reaching far out into the Atlantic Ocean 

 from both the eastern and western sides. 



