144 PROF. E. HULL, LL.D., F.R.S., F.G.S., ON 



was followed by several minor oscillations resulting in the 

 present arrangement of land and sea. The distribution of 

 the land fauna and flora seems also to be corroborative of 

 Professor Spencer's views. 



Sucli conclusions are sufficiently startling; but for myself, 

 I do not see how they are to be controverted. The sub- 

 merged terraces, and profound valleys by which they are 

 traversed, are such as could only have been formed under 

 sub-aerial conditions ; it is impossible to conceive of their 

 formation while under the waters of the ocean.* 



The evidence of the former greater elevation of the 

 American coast finds its counterpart in that of Greenland 

 and the plateau on which stand the British Isles and Scan- 

 dinavia defined by the 100-fathom line. That this plateau 

 was a land surface drained by rivers continuous with the 

 Rhine and others has been shown by Godwin-Austen, 

 Professor T. Rupert Jones, and more recently by Mr. F. W. 

 Harmerf ; while as regards Greenland, Mr. T. C. Chamberlin, 

 of America, has recently stated that " there is no ground to 

 question the former elevation of Greenland."! It would 

 therefore appear that the elevation which affected the 

 eastern coast of the American Continent was continuous all 

 round the northern and western shores of the North Atlantic. 

 The views of Mr. Warren Upham tend to confirm this 

 conclusion. § 



As regards the period when these " stupendous changes of 

 level " took place, Professor Spencer says that they reached 

 their culminating point in the Post-Lafayette, or early 

 Pleistocene epoch of Eastern America.|| For the grounds of 

 this conclusion the reader must be referred to Professor 

 Spencer's memoir itself. 



It has been suggested to me by more than one friendly 

 critic that the submerged terraces and river-valleys have 

 required a longer period for their formation than one special 



* Professor Spencer considers that the floors of the Gulf of Mexico and 

 of the Caribbean Sea were converted into plains. This does not appear 

 to be a well-founded conclusion ; they may have been inland seas during 

 the continental pei-iod as shown on the accompanying map. 



t " The Pliocene deposits of Holland, etc.," Quart. Journ. Geol. Soc, 

 November, 1896, p. 748. 



I " Eecent Glacial Studies in Greenland," Bull. Geol. Soc, America, 

 vol. vi, p. 219. (1895.) 



§ " Causes of the Ice Age," Journ. Vict. Inst., vol. xxix, p. 201. 



II Stipra cit., p. 307. 



