F 3 we 
Geology of Harpeth Ridge, Temeaste 223 
besides several species not described, and angle microscopic coral- 
lines.. As regards their lithological ¢ , there was observed. 
sufficient resemblance in their color os texture, to lead to the 
conjecture of their correspondence, | before examining the fossils. 
Immediately above this, occurs a yellowish brown calcareous 
rock, about ten feet -in thickness, containing numerous small 
cavities, filled with quartz crystals. 
In this were found no fossils, except in the upper stratum, 
where were obtained a small Orthis in great abundance, several 
species of coral, a Delthyris and Cyathophyllum, — Next in order 
is a red limestone, which on disintegration furnishes a material, 
resembling Spanish brown. The red color of many of the mi- 
eroscopic shells mentioned above, suggested an examination in 
this rock. In it were discovered the Cyclora and Nucula. 
Thickness from six to eight feet. 
The next formation identified was a peculiar one, correspond- 
ing with a portion of the Niagara group of New York, develop- 
ed at Lockport, and usually termed the red encrinal limestone. 
It is composed chiefly of fragments of encrinital columns, many 
of which are colored red. Being perfectly familiar with that at 
Lockport, I have little hesitation in pronouncing this the same, 
for they possess peculiarities of color. and structure not easily 
mistaken—the latter being furnished by the fracture of the’ 
plates composing the encrinal columns. Allowing that some of 
the formations of New York are wanting here, its stratigraphical 
position is also favorable to this conclusion. It is about twenty 
feet in thickness. Above this, is found a light snuff-colored 
rock, which also contains the microscopic shells ; and on examina- 
tion with a powerful magnifier, it seems almost entirely compo- 
sed of them. From this they are doubtless chiefly furnished, as 
its color corresponds with the marl and disintegrated rock in 
which they are found, as also the color of the shells, except some 
that are red. This, on the north side of the ridge, is but three 
or four inches thick, but on the opposite side, about one mile 
south, it is about fifteen inches in thickness. 
Next occurs a stratum of shale from twelve to fifveert feet in 
thickness. Although upon minute examination, no traces of 
organic remains were found in it, yet there is little doubt of its 
identity with the Marcellus chalene or & pyritiferous” of Eaton in 
New York, as will be seen when its position is more fully de- 
scribed. Ata place several miles below this, on the east. bank 
