INSTITUTE OF SCIENCE, PHILADELPHIA. 1 25 



Eopliora quadricostata Say. 

 Fusus quadricoslatus Say, Journ. Acad. Nat. Sci. Phila. iv. p. 127, pi. vii. fig. 5, 1S24. 

 Ecphora quadricostata Conrad, Proc. Acad. Nat. Sci. Phila. i. p. 310, 1843 ; Mioc. Foss., p. 

 S4, pi. 48, fig. 2, 1845- 



Miocene of Maryland, Virginia, the Carolinas, the upper bed at Alum 

 Bluff, West Florida, and possibly the silex-beds at Ballast Point, Tampa Bay. 



What GrypJicea costata is to the Cretaceous and Vencricardia planicostata to 

 the Eocene, this shell may be said to be to the Miocene of the Atlantic coast. 

 That is to say, its presence in undisturbed strata is sufficient evidence of 

 their age. 



About twenty years ago Dr. R. E. C. Stearns collected on the shores of 

 Tampa Bay and its arm, Hillsboro Bay, where the most noted exposure of the 

 silex-beds occurs. Long Key is a mere dry expanse of sand thrown up by 

 the waves and protecting Tampa Bay, but containing, as far as known, no 

 solid rock of any sort. It lies between the sea and the southern part of 

 Tampa Bay, off the Manatee River. On the shore of this key Dr. Stearns 

 collected a fine, perfect specimen of Ecphora, now in the National Museum. 

 It has much the appearance of the silex-bed fossils, which are washed out 

 of the marl, drifted with the roots of trees undermined and carried away by 

 storms, and spread rather widely like recent shells on the shores of Tampa 

 Bay. The rocks older than the silex-beds of this vicinity are of a different, 

 very yellow color, their fossils are represented almost wholly by molds, and 

 if present are, as a rule, not silicified. At that day collectors had not invaded 

 the region mentioned, and as there seems absolutely no outside source from 

 whence the Ecphora might be derived, I feel justified in referring it to the 

 marl of the silex-beds, though it was not actually taken out of the marl by 

 Dr. Stearns. It could not have floated far, owing to its size and weight, 

 for the surf outside of the bay is always heavy. The only alternative seems 

 to be that it might have come down the Manatee River in flood-time, with 

 some tree from the Rocky Bluff Miocene beds. But Miocene beds in which 

 the shells are thus preserved are not known in this part of Florida, and the 

 weight of probability seems to connect the specimen with the silex-beds, al- 

 though a careful examination shows that it is not silicified. 



Genus FUSUS Lamarck. 

 Subgenus Papillina Conrad, 1865. 

 Tiirrispira Conrad, Smithsonian Checklist Eocene Foss. U. S., p. 19, 1S66. 

 Clavifusus Conrad (sp.). 



Fusus (Papillina) dumosus Conrad. 



Plate 10, figure 6 a. 



Strepsidura diimosa Conrad, Proc. Acad. Nat. Sci. Phila. vii. p. 262. Wailes, Geol. Miss., 



p. 289, pi. 17, figs. loffi, 106, 1S54. (Jackson group.) 

 Papillina mississippiensis Conrad, Am. Journ. Conch, i. p. 17, 1865. 



