CENozoic (marine). 277 
principal characteristic of this upper layer is the multiplication 
of the nuramulites, and the gradual disappearance of the orbi- 
toides. In rocks about Levyville these are wholly wanting. 
There are also some peculiar radiata." 
MIOCENE. 
As regards the strata of this age along the Atlantic coast, we 
have nothing to add to what has been set forth by Prof. Heilprin,* 
who recognizes a practically continuous belt of post-Eocene Ter- 
tiary beds extending from New Jersey to South Carolina, and 
probably on into Florida. While differences have been noted in 
the shells of these beds in the different States, Prof. Ileilpria 
-refers them to the Miocene. 
In Florida, rocks of this age have been known for some time, 
and from different localities, chiefly until recently, from the east- 
ern side of the peninsula. More recently they have been seen 
by Johnson, Heilprin, and Dall, also in the western and southern 
parts of the peninsula ; and Professors Heilprin and Dall have 
lately shown that much of what was formerly considered as Eocene 
and Oligocene on the western coast, near Tampa, is probably 
Miocene. 
Mr. Johnson has also observed the materials of this age occu 
pying depressions in the Eocene limestone, for instance near 
Gainesville, and some of the Miocene deposits of the southern part 
of the peninsula lately observed by Heilprin may also hereafter 
be found to rest upon Eocene rocks. It is a matter of interest 
to note that the greater part of the materials collected from some 
of the deposits of this age, especially in the central parts of the 
State, hold, both in the shell casts and the matrix, a high per- 
centage of phosphoric acid, and underlie, and give origin to 
the fertility of, the High Hammocks. On the eastern coast this 
belt of Miocene rocks is probably continuous with the Miocene 
of Georgia, South Carolina, and other States of the Atlantic 
coast. 
In the other Gulf States no deposits referable to the Miocene 
have as yet been observed, with the exception already noted, of 
the Grand Gulf beds of Mississippi and the States to the west- 
ward. On account of the dearth of fossils in this division and 
* U. S. Tertiary Geology. 
