of the United States. 39 
adoption. 'The Buhr stones, which are used extensively in 
the western States, and are obtained on Racoon creek; at 
Huntsville, and many other situations, belong to a very dif- 
ferent formation ; they are composed. of chert, containing 
an enormous quantity of organic remains of encrini, and 
consequently are more ancient than the Georgia stone. . 
4. London Clay. od 
In the banks of James river, Va. there is a large quantity 
‘of organic remains imbedded in a bank of clay. _ At Rich- 
mond are found fossil triangular teeth, apparently belonging 
to sharks, and other pieces of bone, at a ‘distance of, sixty 
feet from the surface. oi Oi i yeta Le 
- All these fossil remains are similar to those found. in the 
London clay, and from the same spot I have seen’ fossil 
shells, similar to those which are deposited in the collection 
of. the Geological Society in London, and which were ob- 
tained in the deep excavations. at Highgate hill. to insas 
t Washington, under the; mass of diluvian gravel, of 
which the higher part of the capitol hill is composed, thefe 
is a stratum of clay, which contains many organic remains. 
Trunks and branches of trees are found ata distance.of fifty- 
four feet from the surface ;, and: farther down the river} in 
digging wells, shark’s teeth are often met, with. An.the cab- 
been observed, and a careful examination would. establish 
tHe similarity of the strata in which they were found. 
s <a i 2 
5. Caleatre Ostrée, ......., sittgiohs 
tion in the world, when we consider. the almost incredible 
quantity of fossil shells which it contains. sted inal 
