Alabama, Georgia. and Florida. 163 
the rock was of the same description, excepting, that it was firmer. 
The only fossil it appeared to contain, was the Exogyra costata. 
In ascending still higher, I observed high clay banks, regularly 
stratified, and sometimes alternating with sand and. pebble beds. 
At one of these, upon the east side of the river, where the steam- 
boat stopped for wood, I collected several samples containing shells; 
among which is a small Ostrea, about the size of the O-crista galli, 
a Mytilioides, a Gryphea, and a Terebratula?, The clay is fine 
grained, of a bluish grey color ; and contains minute scales of white 
mica. 
In approaching astcomery, a continuous bluff of more than a 
mile in extent, and upon which the town is situate, comes into view. 
Its height, where the river passes under it, is from sixty to eighty 
feet; and its almost perpendicular face of red gravel and sandstone, 
presents a very striking contrast with the green forest by which its 
summit is crowned, and with the dark current flowing by its base. 
This bluff is almost entirely made up of ferruginous sand, arranged 
in layers distinguishable by the shade of red or yellow which they 
present, and occasionally agglutinated by hydrous oxide of iron, so 
as to form a tolerably firm sandstone. The materials of this forma- 
tion are almost exclusively quartzy, consisting of small grains, rarely 
larger than a pea, and invariably deeply stained by oxide of iron. 
In a few places, alternations of what I consider the Plastic Clay, 
were noticeable. ‘The sand and sandstone did not contain, so far as 
I could discover, any fossil remains, whatever. 
In crossing the Chattahoochee River, at Columbus, where the 
banks are high, I noticed the same red gravel, sand and clay, as on 
the Alabama. In passing the ferry, the newly constructed piers of 
a bridge to be thrown over the river, were seen to be built with 
gneiss; and this rock was soon abundantly discovered in place, on 
my road to Milledgeville. Indeed, large blocks of quartz rock and 
pieces of granite were seen all along upon the road. In crossing 
Flint River, gneiss was seen in place. At Clinton, 1 remarked 
boulders of greenstone. 
In approaching Augusta from the south west, across the sandy 
plains, when within four and a half miles of the city, I passed what 
is called a limestone quarry. Being in a public conveyance, it was 
out of my power to examine the locality, otherwise than from sam- 
ples of it afterwards seen at Augusta. It presents the strongest 
analogy, on the whole, to the Upper. Fresh Water Limestone. The 
