he: 
222 Geolozy of Harpeth Ridge, Tennessee. 
Art. VIII.—An account of the Geology of Harpeth Ridge, Da- 
vidson Co., Tenn. ; by 1. N. Loomis, Franklin College, Tenn. 
>, 
Dorine a geological exploration of a few days, by a number of 
the students and faculty of Franklin College, Tennessee, a few 
observations and discoveries were made, an account of which 
may be of interest to the readers of your Journal. 
The college is four miles east from Nashville, and our course 
from this point was in a southwesterly direction, on the old 
Franklin road to the Harpeth ridge, bordering the Harpeth river, 
a branch of the Cumberland, entering it about twenty miles be- 
low Nashville. 
he formations of this region, belong to the Lower Silurian, 
and we were able to identify most of them with the correspond- 
ing ones of New York and Ohio. The first of these was that 
corresponding with the blue shaly limestone of Ohio and Ken- 
tucky, and exposed for several miles around Cincinnati, which, 
according to Mr. James Hall, is identical with “the rocks of the 
Mohawk and Hudson valleys in New York.”* 
Tn Middle Tennessee, the rocks dip to the south, and we came 
on to this one at the base of the ridge, which at this place is 
from fifty to sixty feet in thickness. The evidences of identity 
between these two formations are full and satisfactory. Two or 
three species of Delthyris; a well defined Trochus; a beautiful 
encrinite ; Orthis testudinaria, O. callactus, and several other 
species ; a very small Atrypa, abundant at Cincinnati, and named 
by the Western Academy of Sciences, Atrypa communis ; numer- 
ous corallines, among which are the Favosites muricata, F. milli- 
poracea, and a beautiful star coral ; Strophomena sericea, 8. alter- 
nata, and one or two others; and a species of Bellerophon, were 
all found here, which, on comparison with those procured at Cin- 
cinnati, could not be distinguished from them, by a close eX- 
amination. 
Were farther proof of their identity wanting, it might be 
found in the microscopic shells in the marly clay accompanying 
them, discovered by Mr. J. Carley at Cincinnati, and described 
by Mr. James Hall in a previous number of this Journal.f 
These were found in large quantities, beautiful and perfect, 
a “ag are 
* This Journal, Vol. xivimt, p. 293. t Vol. xzvu1, No. 2d. 
