22 EARLY MAN IN BRITAIN. [CHAP. n. 



chapter. 1 Mr. Starkie Gardner places the land barrier 

 which shut off the Atlantic from the Arctic Sea, between 

 the 60th and 70th degrees of N. latitude, or in the 

 position in which it is represented in the accompany- 

 ing map (Fig. 3). 2 



The forms of animal life also common to Britain and 

 America prove a connection between the two regions in 

 the Eocene age. The opossum of Eocene Britain, the 

 extinct Coryphodon, Lopliiodon, Anchithere, and Ano- 

 plothere, are common to both, and the alligator, which 

 haunted the rivers of the south of England, the bony 

 pike, the last representative of the armour-clad fishes of 

 the Secondary period, and a little snail (Helix labyrin- 

 thica), have found a refuge in America from those agencies 

 by which they have been exterminated in Europe. 



For the migration of these animals there must have 

 been a continuous tract of land between Britain and 

 America ; and the direction of this is pointed out by the 

 soundings in the Atlantic and the Northern seas (see Map, 

 Fig. 3). It is indicated by the ridge of land at a depth 

 of 500 fathoms sweeping away northwards from the 

 west of Ireland, past the Faroe Islands to the south of 

 Iceland and Greenland. On the eastern side of this the 

 observations taken in the Norwegian Deep Sea Expedi- 

 tion in 1877 prove the existence of deep water between 

 Jan Mayen Land and Spitzbergen, and between that 



1 If the fossil floras of the Polar regions be judged from the stand- 

 point offered by the decrease of temperature from the equator towards 

 the pole, they are Eocene. If, however, we look at them, homotaxiaUy, 

 from the point of view offered by the European Meiocenes, they are 

 Meiocene. Mr. Starkie Gardner takes the former, Dr. Heer the latter, view. 

 See Starkie Gardner, Nature, xix. 124 ; xx. 10. 



2 This map was drawn in 1875, and its accuracy is confirmed by the 

 independent reasoning of Mr. Starkie Gardner. 



