Trans. N. Y. Ac. Sct. 8 Oct. 15, 
ments, the speaker passed to the study of similar objects in this 
country, with special reference to the discoveries of Dr. C. C. ABBOTT 
in the river gravels at Trenton, N. J. During the past summer, the 
speaker had visited the localities near Trenton, and had conference 
with Dr. ABBOTT on the whole subject of his studies thereabout. (A 
black-board map was here employed to show the position and limits 
of the “ river gravel” along that part of the Delaware Valley, in dis- 
tinction from the earlier ‘‘ yellow gravel,” probably marine Tertiary, 
which covers much of the region of Southern New Jersey.) 
Dr. ABBoTtT had long been interested in gathering the Indian relics 
(neolithic and modern), which are found in great abundance on and 
near the surface of the country all about Trenton. Some years since, 
after reading the works of Sir JOHN LUBBOCK, he began to pursue the 
study more systematically and with growing enthusiasm, having 
entered into correspondence with Sir JOHN LUBBOCK, and sent him 
from time to time specimens of the implements, to the number of many 
hundreds. In this correspondence and study, it soon became apparent 
to both gentlemen, that a marked difference existed among the speci- 
mens. The majority of them were of the ordinary ‘‘ Indian arrow- 
head ” type, fairly wrought from flint, hornstone, or quartz; but a few 
were found of much ruder shaping, and made of a dark, compact argil- 
lite. Careful search and comparison soon revealed the fact of a cor- 
responding difference in the mode of occurrence of these two forms, 
the ordinary ones being found on or near the surface, in ploughed 
fields, etc., while the rough argillite specimens were obtained only at 
a few points along the immediate river bank, and had, to all appear- 
ance, fallen or been washed out of the gravel bluff, which is some 30 
to 50 feet high. Upon this, Dr. ABBOTT made his first published an- 
nouncements of the discovery of remote pre-Indian relics in the river 
gravels, and connected those beds with the floods derived from the 
melting ice of the Glacial period. 
So important a claim, naturally, was not suffered to pass unchal- 
lenged. The objection was raised at once, that proof was lacking of 
the actual occurrence of these implements in the gravels proper,— 
that they might have been washed down from the surface. The next 
stage of the investigation, therefore, was to search for the implements 
in situ; and it was not long ere they were successfully discovered, 
imbedded in, or projecting from, the gravel-bank, at depths of several 
feet below the present surface of the country. About this time, the 
Pennsylvania Railroad Co. began excavating and cutting away the 
gravel-beds at several points near Trenton, thus exposing large and 
fresh sections of perfectly undisturbed material, and affording greatly 
increased facilities for exploration. Dr. ABBOTT was not slow to im- 
