196 TRANSACTIONS OF THE [Apr. 24 
eighty miles, instead of with the near-by coast of New England, 
not more than twenty miles away.* : 
We therefore have to consider the fact of a characteristic 
flora, whose principal habitat is on the mainland southward, 
extending from New Jersey on to Staten Island, thence on to 
Long Island and the islands to the eastward, and then reap- 
pearing on the mainland again in a limited area in southeastern 
New England. We have further to consider the significant fact 
that while in its northward extension it is a coast flora entirely, 
southward it exists not only near the coast, but over an area 
many miles inland, This significance will be better understood 
and appreciated when the geology of the region comes to be 
discussed. Considering the flora alone we might readily 
imagine a continuous strip of mainland to exist through the 
region now occupied by it, while Connecticut, with its little 
adjacent areas of New York and New Jersey would represent 
a more or less isolated island. 
What, then is the most reasonable explanation of these 
botanical facts which we have established? Suppose we see 
what the geology of the region can tell us. 
PART IL: ¢ 
During Cretaceous and Tertiary times a series of fresh water 
or estuary and marine deposits (clays, sands, gravels and 
marls) were laid down along the eastern borders of the North 
American continent. About the close of the Miocene, or the 
beginning of the Pliocene period, an era of elevation began 
which finally raised them hundreds, in places thousands of feet, 
above their present level, forming a vast coastal plain, which 
extended over the entire area where we now find them, and for 
a considerable distance eastward, into what is now part of the 
*“ Catalogue of Plants Growing Without Cultivation in the County of Nan- 
tucket, Mass.” 
“The Pine barrens, although farther south, are of similar structure, and 
Nantucket, as regards its flora, seems like a piece of New Jersey moved up the 
coast for the convenience of northern amateurs in botany, who cannot get away 
from business long enough to go collecting in that State ‘ : : Trees 
are lacking except in stunted form, and there are few of those, yet the tradition 
is that the island was well wooded when the first settlers cameini659 . . , 
Some wood plants probably died out soon after the trees that sheltered them 
were gone; but even now Nantucket, though treeless, is not a flowerless isle 
5 5 The island flora interests all botanists fromits peculiarity . . . 
they are surprised at the occurrence of species not to be expected in this 
latitude . : some belong to more northern loealities, but these are 
far less numerous than the southern plants, some of which have never been 
found elsewhere in New England.” 
