PREFACE. 



The Wagner Free Institute of Science, in its object to promote the cause of Science 

 by encouraging original research and publishing the results, now issues the third volume 

 of its Transactions, containing a description of fossil mollusca collected in Florida. 



For the present, the Trustees of the Institute have considered it desirable to devote 

 part of its available means to the exploration and investigation of the comparatively little 

 known field of the geology and pateontology of Florida, which form the chief subjects of 

 the former volumes of the Transactions as well as of the present one. 



In the tertiary beds of Florida recently explored, there have been discovered many 

 new and interesting fossil mollusca, forming the material of Mr. Ball's contribution, 

 which will be found to be an important addition to the literature and knowledge of the 

 tertiary fauna of our country. The paper embodies the results of the labors of several 

 collectors ; to whom the Institute desires to express its obligations ; but especially to the 

 U. S. Geological Survey, for the permission to use much of the material collected in 

 Florida under the direction of the Survey. 



JOSEPH LEIDY, 

 President of the Faculty and Director of the Bluseum. 



