350 INHABITANTS OF THE ANCIENT LAKES?. 



'*> 



(aided, probably, by an earthquake) forcing a passage 

 down the present bed of the St. Lawrence." 



That enterprising officer, Major Long, of the corps 

 of engineers, forwarded to me a box of minerals and 

 fossils from the Illinois river and its vicinity, and from 

 the region adjacent to the junction of the Missouri and 

 Mississippi. Organic remains of bivalve molluscas, and 

 of some other beings, probably animal, to me unknown, 

 are contained in the flinty masses along the Illinois its 

 whole course, from Chicago, near lake Michigan, to the 

 Mississippi ; and shells and madrepores abound in the 

 limestone around St. Louis, and down the Mississippi to 

 St. Genevieve and beyond. 



In the geological chapter of the Picture of Cincinnati 

 ly Daniel Drake, M* D. (p. 6467), the strata through 

 the extensive region of which that district is a part, are 

 represented as a secondary form " a vast precipitate 

 from a lake or sea of salt-water." It is a limestone of 

 two kinds, one ancient and the other modern. The lat- 

 ter, of a grayish-blue colour, surrounding Cincinnati, 

 contains, according to this respectable writer, vestiges 

 of the following species: 



Anomia terebratula. 



placenta. 



Belemnites. 



Ammonites. 



Entrochites, in flint. 



Corallines, in flint and limestone. 



Madrepores, 



, . always siliceous. 



Tubipores, $ 



With many other kinds, which Dr. Drake supposes a 

 skilful naturalist could ascertain. 



