J. Brysen—Gtlacial Phenomena of Long Island. 169 
‘ ConcHIFERA— ConcHIFERA—continued. 
Avicula inequivalvis. Modiola scalprum. 
Cardium multicostatum. Ostrea, sp. 
Cardium truncatum. Pecten equivalvis. 
Cucullea, sp. Pecten liasinus. 
Gervillia levis 2 Pholadomya Hausmanni. 
Goniomya V-scripta. Pleuromya unioides. 
Inoceramus, sp. Spondylus spinosus. 
Leda longicaudata. 
Lima pectinoides. PLANT xZ— 
Modiola Hillana. (Wood). 
ViL—Tue Gractan Poenomena oF NortH AMERICA, AS STUDIED 
in Lone Istanp, New Yorg, U.S. 
By JoHN BRYsEN, Esq. 
: AVING resided for some years past on Long Island, the terminal 
moraine of the Great American continental glacier, and having 
given considerable attention to the drift phenomena, I am convinced 
that no oscillation of the continent has taken place subsequent to the 
Glacial period ; and that the river kames, with their assorted gravel, 
etc., can be accounted for, without resorting to any such doubtful 
interpretations. I am aware that the presence of shells in the 
Boulder-clay argues in its favour; but that shells become mixed 
with the drift while the glacier is in motion is evident from what 
Prof. Geikie saw in Scandinavia. I will now try in a brief way 
to give your readers the result of my observations; and, though the 
sketch may be somewhat crude and imperfect, it may serve to throw 
a little light on this difficult problem. 
Let us imagine a great ice-sheet some 10,000 feet in thickness, 
covering the eastern half of the North American continent. It 
begins to move from the region of Lake Superior, and, after a lapse 
perhaps of some 25,000 years, its terminal moraine ends in the sea, 
and stretches along the whole length of the Atlantic border from 
Jersey to Nova Scotia. It must have been much higher than now ; 
and as the ice began to melt, vast streams of muddy sediment washed 
down in front of it, forming what is now known as the ‘south side’ 
of Long Island. Behind the moraine the waters of the melting 
glacier were dammed up, and were trying to cut their way through 
the rocky débris in front of them. Previous to the Glacial age the 
waters of the Hudson, Connecticut, and other rivers, must have 
flowed directly into the sea, and as this barrier was piled up in 
front of them, new channels had to be formed, the existence of 
‘which is still visible in the low marsh-lands throughout the interior 
of the island. Underneath the glacier wild and turbid streams 
fought their way to the sea, almost, and at some places altogether, 
penetrating the main ridge, or what is now known as the backbone 
of the island. The Sound, or East River, did not yet exist, and 
the waters flowed around not through Hurlgate as at present. Vast 
basins at Maspeth and Hunter’s Point received the waters from 
above, and, in fact, all the bays and numerous streams were con- 
‘nected from Flushing to Gorvanus. Most of what is now the City 
