TRIASSlfc PERIOD. 



441 



dry land stretched farther out to the eastward, and that the sea- 

 shore deposits were formed, but are now submerged. A change of 

 level of five hundred feet would take a breadth of eighty miles 

 from the ocean and add it to the continent. 



This important fact — which has been before referred to more than 

 once, on account of its bearing on the history of the continent — 

 is presented to the eye in the accompanying map, copied from one 



Fig. 664. 



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Map of the submerged border of the continent off New Jersey and Long Island, with lines 

 of equal soundings in fathoms; NY, City of New York. 



of the charts of the Coast Survey under Professor Bache. The 

 coast-line on the north is the south shore of Long Island ; that on 

 the west, the coast of New Jersey ; while the Bay of New York (at 

 the mouth of the Hudson) is near the junction of the two (below 

 NY). The dotted lines are lines of equal soundings, indicating 

 depths of 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120 fathoms. These 

 lines run back in a long loop northwestward towards New York 



