Corres])ondence. 133 
years along the whole extent of the terminal moraine on Long Island, 
and the longer J study the more I am convinced that these depressions 
are in some way related to sub-glacial or super-glacial drainage. 
The "ground moraine landscape" (= our terminal moraine) and the 
hills and ridges of sand and gravel, the German DurchragungHzuge und 
knme, owe their moditication to these glacial rivers, and I believe with 
professor Salisbury that they are closely associated in time of origin. 
I cannot think that pressure has had much to do with the formation of 
these moraine ridges on Long Island, as the material does not appear to 
be bulged tip as intimated by Dr. Wahnschafle, although there are a few 
writers who think they see evidence of pressure, and attribute the form- 
ati m of some of the kame moraines, on the north side of the island, to 
lateral thrust. I cannot think so. 
It seems as if the debris had been carried along with, and in the ice- 
sheet, and as it fell from the grasp of the glacier much of it was assorted 
over by sub-glacial currents, and washed out from its terminal front, 
forming what is known as the south side of Long Island ("overwash 
plains, whose surfaces show little relief"), yet the streams that issued 
from the front of the ice-sheet can be traced from the terminal moraine 
to the sea, and in places there are some conspicuous ridges which seem 
to run under the ocean, for Prof. Agassiz writing to Elie De Beaumont says, 
"the submarine dykes along our coast would be osars if they were ele- 
vated." These professor Wright calls kame deltas while the huramocky 
ridges connected with our terminal moraine the late H. Carville Lewis 
would designate "marginal kames." These marginal kames are always 
more prominent where the flood of waters was greatest, and are pushed 
further to the south, as may be seen near Fort Hamilton. Where the 
streams were not so powerful, the "ground moraine landscape," our ter- 
minal moraine, ends more abruptly and the kettle-holes are more com- 
plete. Where the waters broke through, as at Hempstead, the terminal 
moraine disappears, and the plain becomes more extensive, and Far 
Rockaway point is the result. 
There is a slight difference of nomenclature among the glacialists of 
Europe and America, but the phenomena seem very much the same. I 
have never observed on Long Island anything that seems to answer to the 
Endmoriine of the Germans, nor such dykes as G. H. Kinahan describes 
as occurring in the counties of Wexford and Carlow, Ireland, and yet, in 
my last letter to the Geologist on Englacial Drifts, I spoke of a section 
iu the Rockaway Railroad cut tliat would seem to combine the three sets 
of phenomena mentioned in the review of Dr. Wahnschaffe's work, the 
Grundmor((nenliindsch((ft, the Endmorane and Durchrngungi^zuge und 
Kdtne. I said: "In the center of the bottom part of the drift is a mass 
of boulders in a sandy matrix, and over this is the hardpan, which is also 
full of erratics. Then comes the modified drift, and over all the engla- 
cial till which was probably laid down after the floods had subsided." 
Thus we see that the same conclusions are being reached by independ- 
ent investigation. John Buyson. 
Eastport, L. /., July C, 18f>2. 
