754 GEOLOGY OF OHIO. 
of itassuch. Prof. Charles H. Hitchcock had also, as early as 1868, 
in an address before the Long Island Historical Society, advanced the 
theory that the line of hills marking the backbone of Long Island is a 
terminal moraine. arly in 1877, in a paper read before the Boston 
Society of Natural History, I was permitted to publish a personal com- 
munication from Clarence King, in which he declared with great con- 
fidence that the accumulations, in the neighborhood of Wood’s Holl, 
and on the Elizabeth Islands, were a true terminal moraine. Mr. 
Warren Upham was the first to go over this whole field from the end 
of Cape Cod to Brooklyn, for the purpose of verifying the hypothesis. 
The results are publisned in volume III of the New Hampshire 
geological reports, pages 8300-305, and in papers read and published in 
the American Journal of Science for August and September, 1879. 
But upon all this the criticis:c could justly be made that the ocean 
was immediately beyond our boundary line, and that the absence of 
glaciation on the bottom of the sea could not be demonstrated. Profs. 
Cook and Smock had, however, a clear field, and in 1878 published the 
results of their investigation in New Jersey, and issued a map correctly 
and accurately showing the terminal moraine, as they prefer to call it, 
across that State. West of New Jersey there had been no continuous and 
accurate investigation of the boundary until 1881, when Prof. Lesley com- 
missioned Prof. H. Carvill Lewis and myself to prosecute the work in 
Pennsylvania. Prof. Lewis and myself worked together in Pennsylvania 
during that summer, and will soon issue a joint report, though the responsi- 
bility of completing the explorations in that State has fallen wholly upon 
my colleague. We went, however, in company over about two-thirds of 
the whole line. In Ohio, Prof. Newberry, in volume II of the report of 
the Second Geological Survey of Ohio, had approximately outlined the 
boundary in that State, but in Ohio, as in Indiana and [!linois, the 
survey was necessarily carried on by a variety of persons, and before 
the most distinctive glacial marks were fully understood; hence, the 
uncertainty about the extent of the glaciated area in those States, and 
of a continuous and more minute exploration of the boundary line. 
The extreme line of special accumulation appears, however, farther 
south than Cape Cod, first in Sankaty Head and Saul’s Hills in 
Nantucket, on Tuckermuck Island, Chappaquiddick Island, and on 
Martha’s Vineyard in the prominent hills extending southwest to Gay 
Head, reappearing again in No Man’s Land, and in a remarkable knot 
of hills on Block Island. In Long Island it appears at Montauk Point, 
