the remoteness of this barrier from the land, and observe that 

 a considerable breadth of deep water intervenes at all points 

 between it and Jeffrey's Bank. If, then, the debris were 

 removed from the bottom of the Gulf of Maine, it would 

 doubtless appear much more clearly than now to be a genuine 

 depression, or basin, shut off from the outside ocean by a broad 

 barrier ; which, whether we consider it to have been, at the 

 time when this gulf was eroded, above the sea, and backed, 

 may be, by an Atlantis, or as having been always submerged, 

 constitutes a serious objection to the view that the erosion of 

 the Gulf of Maine has been effected wholly or mainly by the 

 waves of the Atlantic. Without intending or desiring to raise 

 the question of the existence in past geologic time of an Atlan- 

 tic continent, it will be shown in the sequel that there are other 

 reasons than those here advanced for believing that the Gulf 

 of Maine was, at least during the period of its formation, land- 

 bordered on the east as well as on the west ; that it was 

 eroded mainly, if not entirely, before the beginning of Pale- 

 zoic time ; and that the rocks bordering this gulf, in Eastern 

 Massachusetts at least, are so disposed about the line which I 

 have denominated the axis of the gulf as to indicate that this 

 line is really the axis of a great anticlinal or series of anti- 

 clinals, the erosion of which, after the usual manner of anti- 

 clinal erosion, has, I conceive, produced the depression in 

 question. 



It has long been known that the rocks- bordering the Gulf 

 of Maine exhibit a general uniformity along the strike. This 

 likeness is usually believed to extend not only to the Paleozoic 

 and more recent sediments and their relations to the crystal- 

 lines, but also to the crystallines themselves, which are con- 

 ceived to be arranged in broad irregular belts, parallel with the 

 axis of the Gulf of Maine, and each of which is, in a general 

 way, of the same age and composition throughout its extent. 

 Careful comparisons of the rocks, especially the crystallines, 

 of these various districts , have never been instituted ; and the 

 prevalent opinion here alluded to, though probably correct, is 



