Castoroides Ohioensis. 387 
the sandstones and limestones, which occur in place a few 
miles farther north — depth unknown. 
The thickness of 2, 3, and 4, is variable, though the bottom 
of No. 3 usually varies little from the depth of eight feet from 
the surface. A glance at the section reveals the true period 
of the deposit, showing conclusively that the whole is a lacus- 
trine formation, made subsequent to the deposition of the an- 
cient drift, (No. 5,) which is characterized by its foreign 
materials, while in the later deposit not a pebble of the size 
of a pea can be found. ; 
The section of the bank of the Sodus canal presents the char- 
acter here given, for the space of a quarter of a mile or more, in a 
north and south direction. To the southward the stratum No. 3, 
With trunks of trees, &c., gradually disappears, and the two 
layers of fine sand are united in one, which is still surmounted 
by the vegetable soil above, and rests upon the drift below. 
This sand is regularly stratified, the lines of division being al- 
Most perfectly horizontal, and very regular. "Towards the 
north the sand generally gives place to clay, with the disap- 
pearance of the fossil woody &c. 
The direction of the fallen trees in No. 3 of the section, as 
Well as of the branches and twigs in No. 2, indicaté that dur- 
ing the deposition of these materials, the direction of the cur- 
Tent was towards the north or north-east; and this is corrobo- 
tated by the fact that the southern part of the deposit is 
Wholly composed of sand, while the clay increases towards the 
north. From what I can learn of its elevation, it corresponds 
very nearly with the “ridge road” bordering Lake Ontario, 
Which I have fully described in my Report on the Geology of 
New York. The portion of country now under consideration 
doubtless formed at that period an estuary through which a 
Considerable body of water flowed into Lake Ontario, and 
"Pon the bed of which has been deposited the sand, fallen 
trees, &c., of this formation. Indeed it appears quite proba- 
that this was a part of a great estuary, through which the 
Vaters of the Cayuga and Seneca lakes flowed into Lake On- 
