92 THE CANADIAN NATURALIST. [Vol. vi. 



Leda) clay of eastern Canada ; and Dr. Dawson has identified 

 these with the Marine clays of Maine. The latter are found in 

 all the valleys near the sea level both in that State and New 

 Brunswick, but have not been traced to any considerable height 

 above the sea. All these clays in New England and the eastern 

 Provinces of Canada are of marine origin, but the Erie clays were 

 probably deposited in fresh-water. In New England as well as 

 Acadia there are masses of superficial materials which underlie 

 these marine clays, and should therefore be older than the Erie 

 clay. Dr. Newberry does not appear to recognize them in the 

 region underlaid by this deposit. These older masses of loose 

 materials present in New Brunswick all the features of unmodified 

 drift, and reach to the tops of the highest hills in the southern 

 counties of that Province. While all the other surface deposits 

 in their arrangement betray to a greater or less degree the sorting 

 power of water, this alone, so far as has been ascertained, is un- 

 stratified throughout. It consists of clay and sand promiscuously 

 mino;led. These finer materials enclose numberless striated stones 

 and ami'ular frao-ments havino; no definite arransrement in the mass, 

 but irregularly distributed throughout it. For a height of two 

 hundred feet above the sea, the Boulder clay has been greatly 

 modified by the action of waves and currents during a period of 

 slow subsidence, and in the valleys it is covered with beds of fine 

 clay. 



The Continental Glacier. — Two theories have been ad- 

 vanced to explain the phenomena of drift, namely that which 

 attributes them to the action of icebergs and ocean currents, and 

 that wherein glacier action plays an important part. If the latter 

 be ignored, it would seem no easy matter to account for some of 

 the characteristics of the Drift in this region, such as the smooth- 

 ing and furrowing of low-lying ledges under the lee of continuous 

 hill ranges ; the striation of the undersides of ledges ; the trans- 

 verse grooving of narrow valleys, etc. Since the topography of 

 the region is not favourable to the formation of local glaciers, 

 there beino- no hi<i;h mountains in or near it, if the Acadian drift 

 resulted from glacier erosion, the glacier would have been a wide- 

 spread sheet of ice, covering the whole surface of the country", 

 similar to those of the Antarctic continent, or of Grreenland. Bivers 

 of ice flow down to the sea-side from the wide fields of compacted 

 snow which covers a large part of the country last named ; large 

 masses of these frozen streams are detached at the coast, and 



