20 Phosphate Rocks of South Carolina, 
Lime, while the coralline beds have 94 per cent. of 
this substance. Green-sand Marls are valuable as a 
mineral fertilizer on account of and in proportion to 
the amount of Potash they contain. 
It is somewhat remarkable that the large deposits 
of Green-sand Marls in New Jersey are in beds of the 
Cretaceous age, whereas the Green-sand of South 
Carolina is obtained from what Mr. Ruffin, Professor 
Tuomey, and Dr. R. W. Gibbes call the Eocene 
Beds ; and it must be acknowledged that we also have 
“followed in their footsteps,’ and have called this 
Carolina Marl Formation a middle age. 
Many years ago we obtained fossils from these beds 
which could not be distinguished from similar forms 
collected in the New Jersey sands or Green-sand Marl 
of the Cretaceous formation; when this discovery 
was forwarded to our friend and colleague, the answer 
received was: “ Be careful! from your short experi- 
ence you cannot pronounce positively.” Now that 
twenty-six years have passed by, and with hammer 
still in hand, we humbly submit to the geologists of 
America, that as the so-called Eocene of the Charles- 
ton Basin does not contain a single species—yet dis- 
covered—of recent or living animals, but several 
known forms of Cretaceous Mollusca, that it should 
belong to an intermediate period, a Sub-EKocene or 
Super-Cretaceous. If we mistake not, Sir Charles 
Lyell called it Cretaceous in 1842. 
The Santee Marls are noted also by all writers on 
these subjects, from the time of Judge Drayton, in 
1802, for a remarkable deposit containing gigantic 
