No. 161.] 
167 
attempted to classify the rocks which they eminently characterize. 
Consequently, judging from deceptive mineral analogy, the forma- 
tion has been referred by some geologists to the New, by others 
to the Old red sandstone of Europe, with neither of which does it 
bear the remotest analogy in the contained organic remains, or in 
its relation to other rocks. Indeed it is far below the strata which 
Mr. Richard C. Taylor, with great appearance of probability, re- 
fers to the old red sandstone, and which are wanting in the third 
district. This conclusion, warranted by numerous data, is of great 
importance, because it bears directly on the question regarding the 
existence of coal veins, and any attempt to discover them within 
the range of this sandstone would necessarily prove abortive. The 
fossils, though few in species, are of the most characteristic kind, 
and enable us confidently to identify certain rocks in Pennsylvania 
and Virginia, and their relative position with regard to associated 
strata when developed in detail, will prove a most important guide 
to the miner in his future operations. 
On the Organic Remains of the Red Sandstone. C, 
It is curious to observe the maaner in which the bed of an an° 
cient sea has been gradually filled up by detrital matter, sand be- 
ing deposited at one time by a particular movement of the waters, 
and mud being brought from another quarter by different currents. 
Ripple marks, which are an infallible evidence of shoal water, 
prove that many of the layers were deposited in ihe bed of a shal- 
low sea. They are so perfectly preserved on the uppermost or 
last formed stratum of gray sandstone near Medina, that we could 
trace the direction in which the currents that produced them flow- 
ed. Upon this surface there is a beautiful fossil, which consists of 
stems or branches joined in a reticulated manner, and having un- 
dulated lateral root-like fibres. This fossil is spread over a con- 
siderable space, and I noticed that in some instances it followed the 
undulations of the ripple marks; it was therefore pliable and pro- 
bably moored by its root-like fibres to a sandy bed, over which a 
current of water ran, producing such impressions as we see caused 
by tidal currents on a sand bar. 
Ripple marks are not confined to this surface, but may be seen 
on a much larger scale, as if the current which caused them had 
been more violent, many feet lower, in the bank of the Oak Or- 
* Of this I propose to construct a genus, under the name of LithodictuoUy and to 
name the species, in compliment to my friend, Dr. T. R. Beck, L, Beckii. 
