BOTANY, CONCHOLOGY, AND GEOLOGY. 53 



this line of terminal moraines ean be further traced 

 very distinctly across New Jersey, Pennsylvania, and 

 Ohio. So that Nantucket was one of the outer line 

 of moraines. It is possible that after a while the 

 southern rim of glacial ice receded a little to the north, 

 owing to a slightly warmer temperature supervening 

 from some hitherto unknown cause; since, at any 

 rate, there is a second or inner line of terminal 

 moraines starting at the middle of the east coast of 

 Cape Cod, following the curved shore appearing in the 

 line of the Elizabeth Islands (which were thus doubt- 

 less of more recent formation than the Vineyard or 

 Nantucket), disappearing beneath the surface of the 

 sea at Cutty hunk, reappearing near Point Judith, run- 

 ning along the southern part of Rhode Island, appear- 

 ing in Fisher's and Plum Islands, and disappearing in 

 Northern Long Island. That Tuckernuck is one of 

 the line of outer moraines, the present writer has no 

 doubt; but he has not observed sufficiently to be able 

 to form a conjecture as to whether Muskeget and the 

 Gravelly Island are also as old as the drift, or of far 

 more recent formation than Nantucket. 



The last question which space will permit touches 

 the probable shape of Nantucket at the time the sea 

 first poured round it and gave it its insular state. It 

 is next to certain that the projections known as 

 Coatue, Great, Brant, and Smith's Points, and the 

 Haulover were not in existence at that time; and that 

 there stood above the level of the sea three if not four 

 islands, namely, Coskata, the body of Nantucket, 

 Tuckernuck, and possibly Gravel Island. What then 

 probably occurred to alter and enlarge the shape of 



