TERTIARY MOLLUSKS OF FLORIDA. 



To the material described by Prof. Angelo Heilprin in the first volume of 

 these Transactions much was soon added by the explorations of Mr. Joseph 

 Willcox, the writer, Mr. Frank Burns, of the U. S. Geological Survey, and 

 others. The number of species from the Plio-Miocene of Florida was, on 

 the whole, about quadrupled, and, particular attention having been paid to the 

 collection of the smaller species, it seemed that, of the Caloosahatchie Plio- 

 cene especially, a nearly complete enumeration of the nioUusk fauna was made 

 practicable. Hitherto the only attempt to monograph the fauna of any 

 Tertiary horizon in the United States, with suitable illustrations, has been the 

 fine quarto on the Pliocene of South Carolina by Messrs. Tuomey and 

 Holmes. This work is unfortunately extremely rare and almost inaccessible 

 to students, and, moreover, owing to the unconsolidated state of the beds in 

 South Carolina, a considerable number of species belonging to the antecedent 

 Miocene were included with the truly Pliocene species. Mr. Conrad and 

 others have supposed, therefore, that the whole of the fauna described by 

 Tuomey and Holmes belonged to the Miocene, and that there is not any 

 development of Pliocene in that state. This opinion was as erroneous as that 

 of the authors criticised, but in the opposite direction. 



For these and other reasons connected with the later and more exact 

 determination of our Tertiary faunas, it was thought desirable to make a 

 thorough examination of molluscan remains of the Caloosahatchie beds, 

 which might serve in some sense as a typical fauna with which those of other 

 horizons might be critically compared and a better knowledge thus attained 

 of the distribution, areal and geologic, of the animals of the Tertiary beds of 

 Eastern North America. 



Toward this end the authorities of the Wagner Free Institute of Science, 

 the U. S. National Museum, under the direction of the Smithsonian Institu- 

 tion, and the U. S. Geological Survey have lent their aid. 



The present paper is intended to include the greater part of the Gastropods. 

 The second part will comprise the remainder of the Gastropods, the Pelecy- 

 pods and Scaphopods in their biological sequence, together with a description 

 of the beds from which the fossils have been derived and faunal lists for each 

 horizon. 



The condition of our Tertiary fauna has been hitherto very unsatisfactory 

 from the redescription of species under several names from different localities, 

 thus increasing the supposed faunal differences between different horizons 

 and geographic areas. The nomenclature used has often been defective and 

 far from up to date, while many fossils have been referred to wrong families 

 and genera, because some of our paleontologists were not well acquainted 



