This is extremely well illustrated in Rockland County, where the gneissic Ramapo Mountains are faced at their southeastern base by a lowland, a somewhat rolling plain, which, however, is bounded on its eastern margin by another highland where the trap of the Palisades rises close by the Hudson River/' In the opinion of Professor Tarr, this region, with the large Adirondack area, at the beginning of the Paleozoic were mountainous lands facing the sea, which stretched away to the westward, and beneath which all the rest of the site of New York State was submerged. The Bulletin of the American Geographical Society, vol. xxviii.

HISTORY

WESTCHESTER

COUNTY

southw

into New western Highland mountains extended northward d along seawar reached y probabl they east England, and toward the d southwestward thepresent const Line. This mountain range extende of it was a alone the eastern part of the seacoast States, and west Adironthe r Whethe . <>Teat sea in the present Mississippi Valley connected, and daeks and this Highland mountain range were ever told in the w'lia! was the actual extension of the two areas, can not be of much of the present state of geological knowledge, the record of later ages. earlv history having been hidden beneath the strata sea beat at However in verv earlv Paleozoic times the waves of the then at were these and ds, Highlan n the western base of the souther an time that at was which area, ack Adirond Least separated from the island in the Paleozoic sea. the relations Professor dames I). Dana, in an inquiry concerning at the concluof the limestone belts of Westchester County, arrives of Lower sion that, with those of New York Island, they are probably assoably comform the age same the Silurian a*e, assigning also to Westchester ciated metamorphic rocks.