OF LABRADOR AND MAINE. 261 



height of the land would not materially change the physiognomy of the continent north 

 of the St. Lawrence River and Gulf, where the tahle land rises abruptly from the ocean as 

 in the arctic regions; it would effect a great alteration in the distribution of dryland 

 south of the parallel of 50° N. Should all the present sea-bottom lying within the limits of 

 the depth of one hundred fathoms be thus raised, the Gulf of St. Lawrence would be rep- 

 resented by a river delta, one mouth in the Straits of Belle Isle, the other flowing out be- 

 tween Cape Breton and Cape Ray. All the submarine plateaux, such as the Grand Bank 

 of Newfoundland, and the banks lying off the coast of Nova Scotia, Maine, and Cape Cod, 

 would be elevated above the sea, and probably form broad plains. Thus the effects on the 

 distribution of life would essentially differ from those of the region north of 50° N. Such 

 a rise and enlarged area of land would, as has been stated by physicists, produce an ex- 

 tension southward of an extreme arctic temperature. While the climate would be greatly 

 lowered, we still have added the proximity of the Gulf Stream, as evidenced by the 

 temperate rather than arctic fauna of the glacial beds of New York and Nantucket, and 

 the more tropical assemblage of South Carolina. Such a blending of hot and cold currents 

 of air and water must have produced even more fogs and a much greater rainfall than now, 

 to feed the enormous glaciers which moved into the sea from oft" the principal water-sheds. 



Thus the snow line descended near the sea level, the shore presented a nearly solid front 

 of glacial ice at least rivalling in height and breadth the enormous glaciers 1000 feet thick 

 and 540 miles long, discovered by Sir James Ross in the antarctic lands. As the ice re- 

 ceded, it left all the marks of intense glaciation, in the appearance of rounded rocks, glacial 

 grooves and moraines, both terminal and lateral. 



II. Lcda Clay. There was a gradual change of level in the sea. At the close of the 

 glacial period the snow line gradually receded from the coast, and the glaciers retreated to 

 the mountains. During the slow and gentle submergence of the land ushering in this 

 epoch, the crude moraine matter was sorted into beds of regularly stratified clays 100 to 

 300 feet in thickness. The lowest beds consequently are the most ancient, as is also evi- 

 denced by the greater prevalence of arctic forms. During this time the sea was filled 

 with floating ice, as at present on the Labrador coast, and the great polar or Labrador cur- 

 rent exerted its full power. The temperature being so even throughout the northern hem- 

 ispheres of the globe, there was a great uniformity in the distribution of life, and certain 

 species enjoyed a wide distribution where now they are restricted to comparatively narrow 

 areas. Toward the close of this period the bison, the Greenland seal, the walrus, and the 

 Vermont whale {Beluga Vermontana), flourished. The Age of great Mammals dated from 

 this early period. An arctic fauna and flora inhabited the coast between the sea and the 

 low snow line, and the flora and fauna which are now found only on our alpine heights, or 

 in cold, isolated spots on the coast of Maine and the northern lakes, then peopled the sur- 

 face of New England and Canada. All the biological features of this epoch partook of an 

 intermixture of the boreal and arctic faunas and floras that are now more distinctly cir- 

 cumscribed into narrower areas. 



We have no evidence of an intercontinental communication with Europe during this 

 period. The remains of the bison, the purely American forms of the lower animals found 

 in the Leda clay, all tend to show that no migrations took place either from Europe or 

 Asia into northeastern America. Then, as now, there was a local facies imprinted on those 

 animals whose remains have survived, exhibiting the same faunal distinctions, and even 

 more strongly marked than now. 



