246 The American Geologist. October, i898 
Below the so-called englacial till there was a coarse layer of par- 
tially stratified material and along the edges of the excavated section 
there were some signs of modification. On the northwest corner of 
the same avenue below the surface till, the whole mass seemed to be 
composed of stratified sand and gravel. 
The moraine is very much broken along this section, as during the 
glacial "floods there were many currents that flowed southward from 
the Wallabout depression and other basins on the north side of the 
island. The gaps in the ridge known as the "clove road," "Hunter's 
fly," and the historic "Jamaica pass" are all in this vicinity. 
The point I desire to make, however, is this: The terminal moraine, 
which is supposed to mark the southern limit of the great continental 
ice-sheet, is more complex in character than the southern series of 
hills sometimes spoken of as "moraines of recession." This would 
liardly bear out Prof. Salisbury's suggestion that, "The exposed por- 
tions of the formation made by the ice-sheet which reached the greatest 
extension (the Kansan) should possess less complex contortion of 
stratified drift than the drift of the regions farther north which was 
afifected by two or more ice-sheets." 
It is true that the secondary moraine on Long Island shows a 
greater amount of stratification, but as stated, it is less complex in 
character than the southern moraine known as the backbone of Long 
Island. The reason for this, I have tried to explain in my "Ups and 
Downs of Long Island."* The glacial or subglacial rivers seem to 
have been more united and powerful on the north side of the island, 
for on leaving the bay depressions the streams became divided and 
ramified in such a way as to produce the diversity of drift along the 
line of the terminal which has generally been referred to as unmodi- 
fied drift. While it is true that the southern ridge shows less signs 
of stratification than the northern series of morainic hills, it is never- 
theless a fact, that the former contains a more complex modification. 
This modification takes place only along the old lines of drainage 
which are generally marked by a profusion of kettle holes, and mar- 
ginal kames, as the late Prof. Carvill Lewis called them. 
Prof. Salisbury in his remarks already referred to, says: "It is 
to be borne in mind, that the ice in many places doubtless destroyed all 
the stratified drift deposits in advance of the territory which it occu- 
pied later, and that in others, it may have left only patches of once 
extensive sheets. It also makes it clear that the relationship of the 
two sets of drift are on the whole less commonplace than they might 
have been, had all the deposits once made by the ice and its accom- 
panying water, escaped decaption." The professor's theory is made 
to favor the duality of the ice age; but if the latter has to depend 
upon such arguments for support it has a very slender basis. I must 
say, however, that no writer has so well described the different criteria 
of the Long Island drift deposits, as I have observed them, although 
*Am. Geologist, March, 1895, vol. XV, uo. 3. 
