TRANSACTIONS OF WAGNER 

 1604 



TERTIARY FAUNA OF FLORIDA 



Mr. Willcox and himself. He recognized in them the first distinctive marine 

 Pliocene discovered in the United States. The present writer in company with 

 Mr. Willcox visited the Caloosahatchie, and subsequent collections were made, 

 especially at Shell Creek, by Mr. Frank Burns, of the United States Geological 

 Survey. A rather full geological account is given by the writer in Bulletin 84 

 of the United States Geological Survey, pp. 142-149, and the area over which 

 outcrops of the Pliocene have been recognized is delineated on the map which 

 accompanies that Bulletin and is reprinted by the courtesy of the Director of 

 the Survey in Part II. of this volume. It is therefore unnecessary to recapitu- 

 late the information which has already been printed as above mentioned. In 

 brief, these beds consist of layers of marl conformable to each other, and some- 

 times gently arched in long, low waves, but otherwise little disturbed. They 

 are unconformably overlaid by Pleistocene sands, and, of course, the upper por- 

 tion of the marls contains more recent species than the lower, and is especially 

 notable for the profusion of specimens of Chione cancellata, Planorbis, Physa, 

 and other freshwater or estuarine fossils. 



The specimens are usually in a beautiful state of preservation, though occa- 

 sionally strings or layers of drusy silica have formed in the marl, entangling 

 the fossils. The Pliocene beds dip gently to the westward, so that those por- 

 tions near the sea are newer than those outcropping near the headwaters of the 

 streams. The older beds, probably because deposited in deeper water, have a 

 larger fauna than the newer ones. This is illustrated by the following com- 

 parison, in the order of the distance from the coast of the locality collected at. 



1. Myakka River. Total, seventy-three species, of which sevent}'-two per 



cent, are recent and none peculiar to the locality. 



2. Alligator Creek. Total, seventy-three species, of which sixty-three per 



cent, are recent and none peculiar. 



3. Shell Creek. Total, two hundred and fifty-six species, of which fifty- 



nine per cent, are recent and seven per cent, peculiar. 



4. Caloosahatchie River. Six hundred and thirty-nine species, of which 



forty-eight per cent, are recent and twenty-eight per cent, are pecu- 

 liar. 



The total number of species enumerated from the Floridian Pliocene is six 

 hundred and thirty-nine, of which three hundred and fourteen are known 

 as recent, thirty-two are known from the lower Miocene of Florida, Vir- 

 ginia, and Maryland, one hundred and fourteen from the upper Miocene of 



