1894. | NEW YORK ACADEMY OF SCIENCES. 11454 
Island and the occurrence there of material representing the 
cretaceous formation. Accompanying the latter of these were 
descriptions and figures of several well recognized cretaceous 
leaves, selected from a large amount of material collected by me 
and others at Lloyd’s Neck, in the vicinity of Glen Cove and in 
Brooklyn. 
Since these were published I have been enabled, in connection 
with the summer school of geology of Columbia College, to ex- 
tend the investigation further eastward along the north shore of 
Long Island and on to Martha’s Vineyard. The results ob- 
tained at this latter locality have already been published* and 
all the palzobotanical material from Long Island has been de- 
scribed and discussed, either in the second contribution previ- 
ously mentioned or in the Bulletin of the Torrey Botanical 
Club. + 
The present paper is designed to further discuss some of the 
geological problems previously outlined, in the light of some 
new facts observed. 
I shall assume that the existence of cretaceous material on 
Long Island can no longer be questioned, in view of the facts 
already brought to light, and that we may now confine ourselves 
to the discussion of phenomena in connection with it, such as 
distribution, method of occurrence, associated rocks and their 
derivation, etc. 
Briefly stated, the hypothesis previously advanced is that the 
entire area now occupied by Long Island Sound, was, until the 
advent of the Ice Age, dry land, representing a portion of the 
Atlantic coastal plain, composed ofcretaceous and post-cretaceous 
strata. The continental glacier, upon reaching this easily 
eroded material, plowed it up and pushed it forward, leaving it 
as part of the terminal moraine, while the area eroded remained 
as a great trough, which, becoming filled with water, we now 
know as Long Island Sound. The material pushed forward 
exists to-day as the contorted clays, sands and gravels, buried 
beneath the bowlder till, while the fragmentary eroded material 
is represented by the more or less hardened ferruginous con- 
glomerates, sandstones, shales and concretions which are scat- 
tered through the moraine and in which have been found the 
evidence of their cretaceous origin. 
* “ Observations on the Geology and Botany of Martha’s Vineyard.” Trans. 
N. Y. Acad. Sci. 13: 8-22 (1893). 
tl. ‘* A New Fossil Palm from the Cretaceous Formation at Glen Cove, Long 
Island.” Bull. Torr. Bot. Club, 20: 163, 169, pl. 149 (1893). 
2. ‘* Some Further Notes unon Serenopsis Kempii.’’ Bull. Torr. Bot. Club, 20: 
334, 335, pl. 166 (1893). 
3. ** Additions to the Palzobotany of the Cretaceous Formation on Long 
Island.’ Bull. Torr. Bot Club, 21: 49-65, pl. 174-180 (1894). 
