GENERAL CONCLUSIONS. 293 



the marine shells, bryozoa, and cirripedes found in the 

 boulder-deposits on the lower St. Lawrence, with the 

 unoxidized character of the mass, which proves subaquatic 

 deposition, with the fact that it contains soft boulders, 

 which would have crumbled if exposed to the air, with its 

 limitation to the lower levels and absence on the hill- 

 sides, and with the prevalent direction of striation and 

 boulder-drift from the north-east. 



3. All these indications coincide with the conditions of 

 the modern boulder-drift on the lower St. Lawrence and 

 in the arctic regions, where the great belts and ridges of 

 boulders accumulated by the coast- ice would, if the coast 

 were sinking, climb upward and be filled in with mud, 

 forming a continuous sheet of boulder-deposit similar to 

 that which has accumulated and is accumulating on the 

 shores of Smith's sound and elsewhere in the arctic, and 

 which, like the older boulder-clay, is known to contain 

 both marine shells and drift-wood.* 



4. The conditions of the deposit of till diminished in 

 intensity as the subsidence continued. The gathering 

 ground of local glaciers was lessened, the ice was no 

 longer limited to narrow sounds, but had a wider scope 

 as well as a freer drift to the southward, and the climate 

 seems to have been improved. The clays deposited had 

 few boulders and many marine shells ; and to the west and 

 north there were deposits of land plants, and on land 

 elevated above the water peaty deposits accumulated. 



5. The shells of the Leda clay indicate depths of less 

 than 100 fathoms. The numerous foraminifera, so far as 

 have been observed, belong to this range, and I have never 



* For references, see Royal Society's Arctic Manual, London, 1875. 

 Fielden, Paper on Grinnel Land. Proc. Royal Socy. Dublin, 1878. 



