TRANSACTIONS OF WAGNER 



1570 



TERTIARY FAUNA OF FLORIDA 



Cytherea cassarina Dall, C. Pitaria (Lamelliconcha) planivieta Guppy, 



Cytherea (Ventricola) Blandiana Guppy, B. 



B, C. Chione Woodwardi Guppy, B, D. 



Chione Walli Guppy, B. 



Total, thirty-nine species, of wliicli twenty-six are fairly well identified species. Two 

 of these are known only from this horizon ; four are believed to survive to the recent 

 fauna, another to the Miocene, and one to the Pliocene. One appeared as early as the 

 Claibornian, and three by Jacksonian time. Twelve of the identified species are also 

 known from the Chipolan horizon, nine from the silex beds, six from Bovvden, and four 

 from the Haitian Oligocene. 



The indications of the fauna may be summed up as pointing to a close alliance to that 

 of the Chipola and Ballast Point horizons, in all probability indicating a stage above the 

 latter and below the former. 



TAMPA LIMESTONE, OR ORBITOLITE BED. 



This stratum is superimposed upon the silex beds of Ballast Point, Tampa 

 Bay, where it may be eighteen inches thick, and extends inland and north- 

 eastward. It underlies the citj' of Tampa, where wells are dug through it, 

 reaching water at a depth of ten feet or thereabouts, the cherty stratum of the 

 silex beds probably serving as a water-table below. The same rock occurs 

 seven miles northeast of Tampa in wells and also on land (S.E. J4 Section 14, 

 T. 29, R. 19) near Orient Station on the railway. Its upper surface is about 

 fourteen feet above the water of Six-Mile Run (or Creek), near by, and about 

 twenty-five feet above the mean level of the sea at Tampa, at the railway 

 wharf, according to late surveys. Its thickness varies more or less in diflferent 

 places, and its greatest thickness I was unable to determine, but suspect it does 

 not exceed twenty feet. The same rock is reported to occur on the Manatee 

 River above Braidentown, and I observed it still farther to the south and west 

 in 1887, about one mile from Sarasota village, on the road from Braidentown, 

 in the gully of a small rivulet about half a mile from the shore of the bay. 

 This rock, which is obviously younger than the silex beds, was referred by 

 Heilprin to the " Yorktown" epoch of Dana or middle Miocene. 



The character of the rock is that of a limestone free from silex, of a loose 

 and porous texture and pretty uniform appearance and consistency. The 

 fossils are mostly represented by external molds, but a few, and particularly 

 the Orbitolite described by Conrad, retain their structure. Many of the fossils 

 of the silex beds appear in the Orbitolite bed, but there is a notable absence of 

 the large corals so common in the lower stratum, and various new forms appear 



