88 TRANSACTIONS OF THE [jAN. 27, 



facts and views given by a number of geologists who have written 

 more or less upon portions of the State, Prof. Smith goes on to 

 say: — ''From specimens collected by meat points widely distant 

 from each other, from the observations of others as quoted above, 

 and from the evidence derived from other sources,! am brought 

 to the conclusion that almost the whole State of Florida, from 

 the Perdido River on the west, eastward and southward, includ- 

 ing the middle and western parts of the peninsula, certainly as 

 far south as the latitude of Charlotte Harbor, has for its under- 

 lying formation the white or Orbitoides limestone of Vicksburg 

 age, the exceptions as yet known being the Post-Pliocene or re- 

 cent limestones forming the Keys and the immediate coast along 

 the western, southern, and eatstern shores, and isolated patches, 

 if not a continuous belt, of Miocene limestone between the St. 

 John's River and the elevated table-lands westward. In many 

 places near the coast in Wakulla County a very finely pulverized 

 marl is mingled with the sand, imparting to it a great degree of 

 fertility; this is the 'Gulf Hammock^ land of which much has 

 been written. From inquiries and from the observations of Con- 

 rad and others, I learn that these hammocks exist all along the 

 coast from Wakulla through Taylor, Lafayette, Levy, and Hills- 

 boro Counties to Tampa Bay. This marl is also of Vicksburg 

 age where I have examined it, and from descriptions which I 

 have had from various sources it seems almost certain that the 

 marls of the Gulf Hammocks in the other counties named are of 

 the same geological age. 



"About Ocala, southward and southwestward, is a belt of 

 'hammock' land, where an earthy, partly disintegrated lime- 

 stone mingles with the surface soil. Reference to tables of ele- 

 vations will show that this hammock land is 60 feet higher than 

 the sandy plain of Ocala. My own observations in the interior 

 confirm the statement of Conrad, with reference to the Gulf 

 coasr, near Tampa, that the Tertiary limestone is certain to be 

 the substratum of all the 'hammock' land. At Rock Spring, 

 however, there is a bluff of limestone some 10 feet in height, and 

 from this I was able to collect a number of fossils. They were 

 submitted to Mr. Heilprin, who determined among them the 

 following species: Pecten madisojims, Venus alveata, CarcUta 

 granulata, Carditmnera arata, Mytiloconcha incnrva; doubt- 

 ful were also Cardium sublineatum and Oliva Htterata. This 

 would make the limestone of Miocene age, as Mr. Heilprin 

 states his belief that no Vicksburg species are associated with 

 the shells enumerated. I do not know that Miocene limestone 

 has been observed elsewhere in the State, but it seems prob- 

 able that it will, upon examination, be found either in isolated 

 patches or forming a continuous belt between the Post-Pliocene 



