on some fossil Bones. 413 
how the bones of the land animals fossilized may be disposed 
with respect to those of the sea. 
If the sea should have occupied any space that never had 
been dry land prior to the sea's being there, the extraneous 
fossils can only be those of sea animals ; but each part will have 
its particular kind of those that are stationary mixed with a 
few of the amphibia, and of sea birds, in those parts that 
were the skirts of the sea. I shall suppose that when the sea 
left this place it moved over land where both vegetables 
and land animals had existed, the bones of which will be fos- 
silized, as also those of the sea animals ; and if the sea continued 
long here, which there is reason to believe, then those mixed 
extraneous fossils will be covered with those of sea animals. 
Now if the sea should again move and abandon this situation, 
then we should find the land and sea fossils above mentioned 
disposed in this order ; and as we begin to discover extraneous 
fossils in a contrary directiqn to their formation, we shall first 
find a stratum of those of animals peculiar to the sea, which 
were the last formed, and under it one of vegetables and land 
animals, which w^ere there before they were covered by the sea, 
and among them those of the sea, and under this the common 
earth. Those peculiar to the sea will be in depth in propor- 
tion to the time of the sea's residence and other circumstances, 
as currents, tides, &c. 
From a succession of such shiftings of the situation , of the 
sea we may have a stratum of marine extraneous fossils, one of 
earth, mixed probably with vegetables and bones of land ani- 
mals, a stratum of terrestrial extraneous fossils, then one of 
marine productions ; but from the sea carrying its inhabitants 
along with it, wherever there are those of land animals there 
