40 Finch on the Tertiary Formations 
_In works upon Geology, when noticing the extent of 
banks of fossil shells which are known to be abundant in 
various parts of the world, that near Tours in France, has 
generally been considered: as:most extensive. It is a bank 
of shells nearly unchanged, nine leagues long and twenty 
feet thick, but in the Southern States of America the stra- 
tum of shells, which is now to be described, extends six 
hundred miles in lengih, from ten to one bundred_ miles 
in width, and if the known measurement in one part of the 
line may be supposed a fair criterion, three hundred feet in 
ness. The principal part of the formation is composed 
of shells, and therefore may be hereafter classed as the lar- 
gest collection of fossils in the world. 
All my information respecting it is derived from Nath’). 
“A. Ware; Esq. member of the Academy of Natural Scien- 
ces, Philadelphia, on travelled over many parts of this 
formation, and paid great attention to its character. »In 
Bartram’s travels to. the Southern States, the commence- 
seen of this wear is mentioned, and the termination of it 
w country is noticed by a writer in Silliman’s 
Jotirndly — this is the first memoir which waces it through 
its whole extent, and the geo are solely indebted to Ma- 
jor Ware for the accoun 
Character. It is a pase of shells, in some situations 
united by a scanty calcareous cenyent, but from b 
shells may be readily detached; in this state it is called by 
the inhabitants a soft limestone, which in the quarry is ea- 
‘sily cut by any edge tools, but becomes harder on exposure 
to'the air. In other parts it presents immense banks of 
loose , tenor fifteen miles in length, without the mix- 
ture of any foreign substance. 
Fossils. This extensive formation is chiefly composed 
of a large species of ostrea, which | believe has not yet 
been described. A specimen of it may be seen in the Phil- 
adelphia museum; it is twelve inches long and two and 
three-quarters wide, and each valve from half to two and 
‘a quarter inches thick— —Major Ware says they occur larger ; 
‘on account of their great size I propose to call them Ostrea 
=. The shells appear but slightly changed by 
nee in the earth, and are in many parts used jor 
e. 
