198 TRANSACTIONS OF THE [Apr. 24 
scooped it out to a great depth in places, and then, either 
carrying it forward in mass, or else pushing and squeezing it 
ahead in a great contorted ridge*, capped by the bowlder till, 
finally left it as part of the terminal moraine. Wherever these 
conditions have prevailed we find the phenomena to he the 
same, and Long Island may be considered as one of the grandest 
object lessons in this connection. 
Just when the period of elevation ended and that of depres- 
sion began, in fact, whether it was previous to, or subsequent 
to that of greatest ice accumulation, is yet a matter of contro- 
versy between authorities, but in either case on the retreat of 
the glacier, we may picture to ourselves the terminal moraine 
forming an elevated ridge extending through Staten Island, 
Long Island and the islands to the eastward, forming a 
continuous. more or less, elevated land connection to the north 
and east, with what remained of the coastal plain sloping away 
from it on one side and a trough filled with the water from the 
melting glacier on the other. It is probable that the ridge 
represented by Orient Point, Plum Island, Gull Islands and 
Fisher’s Island may be the remains of an independent second 
glacial moraine, as urged by Warren Upham{ and N. S. Shaler, 
but the discussion of this fact need not now concern us. 
The old river valleys had become blocked up with the débris 
of the moraine, and the waters had to seek other outlets. These 
would naturally be where they first began to overflow the rim 
of the trough in which they were imprisoned. One of these 
would probably be through the old channel of the East River, 
which was to the north of the terminal moraine, and, therefore, 
comparatively free from obstruction. From here the waters 
would join those of the Hudson, which had doubtless ere 
this forced its way, through the morainal barrier and was again 
occupying its old channel. Others are indicated to the eastward 
* Dr. Fredk. J. H. Merrill was, I believe, the first one to thus interpret this 
phenomenon on Long Island; for which see his paper ‘On the Geology of Long 
Island.” [Ann.N. Y. Acad. Sci. iii., 341-364.] It has been made the subject of 
careful personal examination in the vicinity of Glen Cove, and similar effects 
were subsequently noted by me and Dr. N. L. Britton_on Staten Island. [see 
Proc. Nat. Sci. Assn. S. I., Nov. 8, 1884, and Trans. N. Y. Acad. Sci. xi., 101.] 
Although so far_as Long Island is concerned these views are not considered 
tenable by Prof. J.D. Dana. [See ‘Phenomena of the Glacial and Champlain 
Periods about the Mouth of the Connecticut Valley in the New Haven Region.” 
Am. Journ. Sei. xxvi., 341-361; xxvii., 113-130.) And they are rejected as 
inadequate on Martha’s Vineyard, according to Prof. N. S. Shaler. [See 
anor on athe Geology of Martha’s Vineyard,” 7th Ann, Rept. U. 8. Geol. 
urV., 296-363, 
_t“ Terminal Moraines of the North American Ice-Sheet.” (Am. Journ. 
Sei xviii., 81-92 ; 197-209.) 
ib as pk on the Geology of Martha’s Vineyard.” (7 ‘Ann. Rept. U.S. G.S., 
296-363. 
