Vlll PREFACE 



that the correlation of the Antillean and continental beds might be discovered 

 and duplication of descriptions avoided. It was found that the connection 

 between the Atlantic and Pacific faunas ceased at about the climax of the Oligo- 

 cene, and that the relations between the faunas were so intimate that the 

 Pacific coast forms could not safely be entirely neglected. This condition of 

 things will account for the references to faunas not strictly Floridian, of which 

 this work contains so many, yet which were essential to the proper under- 

 standing of both the paleontological and geological evolution of the region 

 concerned. 



The accumulation of material has been so constant and so great that, if the 

 work were to be begun now for the first time, it is probable that the number of 

 species would be greatly increased in the gastropod groups treated of in Parts I. 

 and II. But this sort of thing would go on forever, so great is the richness of 

 our Tertiaries, and an attempt to include the novelties thus passed over would 

 have prolonged indefinitely the task in hand. Enough is known to render such 

 a course unnecessary for drawing the broad conclusions which form the most 

 important result of these studies. For the details of these, too extensive to 

 be properly included in a preface, the reader is referred to the general sum- 

 mary of results at the end of this volume. Here it may be said that, among 

 other things accomplished, several distinct Oligocene faunas have been worked 

 out with fulness and their relations established; a wide extension has been 

 given to the Pliocene deposits, long confused with those of the upper Miocene ; 

 the geological relations of the beds between the Vicksburgian and the Pleisto- 

 cene have been established in their main lines more clearly than has hitherto 

 been the case in the region studied"; the species of half a dozen faunas have 

 been revised, their nomenclature modernized, many new forms recognized, 

 described, and figured ; old confusions have been cleared up, old errors rectified, 

 and a substantial advance in the Tertiary paleontology of our southeastern 

 coastal plain has been secured. 



In a work including such a host of details it would be unreasonable to 

 expect that the author has not occasionally erred. Nor is it to be supposed 

 that in matters where confusion has reigned the author's judgment will prove 

 infallible, or to the taste, in every instance, of others who may study the same 

 data. But, with all such allowances made, it is probable that for future stu- 

 dents (may their tribe increase) the way to an understanding of the subject has 

 been made much easier than it was eighteen years ago. 



The fact that the generally accepted Tertiary column of 1885 was really a 

 sort of skeleton or scaffolding, in which the accepted divisions were merely the 



