rficial and almost imperceptible. They are
generally circular, but some are ovoid. Some have the edge equally
raised around, as if struck by a perpendicular drop; and others
have the edge on one part faintly developed, while another part is
very sharp and well defined, as if the drop had struck obliquely.
It has been suggested, that these fossil rain-drops may have been
made by particles of hail; but I think the variety of size and
depth of depression would have been more considerable if thus
made.

Although we have necessarily treated the subject of fossil
footmarks in a very brief way, sufficient has been said to show
that this new branch of Paleontology may lead to interesting
results. The fact that they are, in some manner, peculiar to this
region, seems to call upon our Society to obtain a sufficient
number of specimens to exhibit to scientific men a fair
representation of the condition of Ichnology in this quarter of
our country; and we have therefore great reason to congratulate
ourselves, that, through the vigilance and spirit of our members,
the Society has the expectation of obtaining a rich collection
of ichnological specimens.

FOSSIL IMPRESSIONS.--II.

Since writing the preceding article, I have been able to obtain,
through the kindness of President Hitchcock, a number of additional
specimens of fossil impressions. By the aid of these, I may hope to
give an idea of the system of impressions, so far as it has been
discovered, without, however, attempting to enter into minute details.
For these, I would refer to the account of the "Geology of
Massachusetts," by President Hitchcock; to his valuable article
published in the "Memoirs of the American Academy;" and to his
geological works generally.

The numerous tracks which have been assembled together in the
neighborhood of Connecticut River have afforded an opportunity of
prosecuting these studies to an extent unusual in the primitive rocky
soil of New England. These appearances are not, indeed, wholly new.
Such traces had been previously met with in other countries; but, in
their number and variety, the valley of the Connecticut abounds above
all places hitherto investigated.

Twenty years have elapsed since the study of Ichnology has been
prosecuted in this country; and, in this period of time, about
forty-nine species of animal tracks have been distinguished in the
locality mentioned, according to President Hitchcock; wh