78 
TKRTIARY SERIES. 
creatures that were permitted to enjoy it, in the 
multitude of shells and hones preserved in the 
strata that were deposited during each of the 
four epochs we are considering. 
M. Deshayes and Mr. Lyell have recently 
proposed a fourfold division of the marine forma- 
tions of the tertiary series, founded on the pro- 
portions which their fossil shells bear to marine 
shells of existing species. To these divisions 
Mr. Lyell has applied the terms Eocene, Plio- 
cene, Older Pliocene, and Newer Pliocene; and 
has most ably illustrated their history in the 
third volume of his Principles of Geology. 
The term Eocene implies the commencement 
or dmcn of the existing state of the animal crea- 
tion the strata of this series containing a very 
small proportion of shells referrible to living 
species. The Calcaire Grossier of Paris, and 
the London clay, are familiar examples of this 
older tertiary, or Eocene formation. 
The term Miocene implies that a minority of 
the fossil shells, in formations of this period, are 
of recent species. To this era are referred the 
fossil shells of Bordeaux, Turin, and Vienna. 
In formations of the Older, and Newer Plio- 
cene, taken together, the majority of the shells 
belong to living species ; the recent species in 
the newer, being much more abundant than in 
the older division. 
To the Older Pliocene, belong the Sub-apen- 
