Mountains, they bend to the south in southern New Eng- 

 land, and conform with the Laurentian barrier just pointed 

 out ; while the remnant that is not cut off in the southern 

 extension, by the Atlantic, finally regains the former strike, 

 and spreads across southern New York and New Jersey. 

 This great Laurentian wall, which is doubtless continuous, 

 under the Paleozoic deposits, from Labrador to Virginia, or 

 beyond, formed the western shore of the ocean, in which the 

 newer crystallines of the Atlantic slope were deposited ; and, 

 subsequently, in its southern half, it became the eastern border 

 of the great Paleozoic sea. It has been a primary axis of 

 continental oscillations, a centre of disturbance — itself undis- 

 turbed. The importance of this ancient Laurentian axis, as a 

 structural feature of the continent, makes still clearer the 

 isolation and unity of what may be called the New England 

 or North-Eastern geological province. It is not intended to 

 deny the existence in New England of the older crystalline 

 formations, for Hitchcock has shown that they certainly occur 

 in the White Mountain region ; but I may safely assert that 

 their occurrence in the western and central portions of this 

 province is always something exceptional. They are not 

 characteristic of any considerable areas. 



This north-eastern province is naturally divisible, in a geo- 

 graphical sense, at least, into two parts, — a south-eastern and 

 a north-western. The division is marked by a line of valleys 

 parallel with, but subordinate to and less distinct than, that 

 isolating the province on the north and west. This axis of 

 depression follows the valley of the Connecticut, from Long 

 Island Sound, to near its source ; then, curving north-easterly, 

 and skirting the northern base of the White Mountains, it is 

 marked by the valley of Lake Umbagog, and the great lake 

 region of Northern Maine, passing to the northward of the 

 Katahdin Range. Entering New Brunswick, it is continued, 

 with the same trend, through the valley of the Restigouch6 

 River and Bay of Chaleur, to the Gulf of St. Lawrence. 

 This secondary line of depression, like the first, is marked 



