﻿THE BIOLOGIC CHARACTER AND GEOLOGIC CORRELA- 

 TION OF THE SEDIMENTARY FORMATIONS OF PANAMA 

 IN THEIR RELATION TO THE GEOLOGIC HISTORY OF 

 CENTRAL MIERICA AND THE WEST INDIES. 



By Thomas Wayland Vaughan, 



Custodian of Madreporaria, United States National Museum, and Geologist in charge 

 of Coastal Plain Investigations, United States Geological Survey. 



INTRODUCTION. 



The following paper presents: (1) biologic summaries for each of 

 the formations for which paleontologic data are available, with 

 brief discussions of the geologic age; (2) geologic correlation of the 

 formations and the distribution of their age-equivalents in Central 

 America, the West Indies, and the southeastern United States; (3) 

 an outline of the paleogeography of middle America. A tabular 

 statement of the age relations of the formations is given by Doctor 

 MacDonald in the preceding paper of this volume, page 528. 



The biologic summaries are based on the paleontologic memoirs in 

 this volume, by Messrs. Howe, Berry, Cushman, Jackson, Canu and 

 Bassler, and Pilsbry, Miss Rathbun, and myself. Dr. C. W. Cooke 

 has furnished me notes on a few of the fossil Mollusca, and I have 

 incorporated in my lists the moUuscan species recorded by Messrs. 

 A. P. Brown and H. A. Pilsbry. I deeply regret that not even a 

 preliminary list of the mollusks that Doctor MacDonald and I col- 

 lected is available. Although I believe such a list would not modify 

 the opinions here expressed, it is needed as a supplement to the other 

 biologic records, particularly in order to supply a basis for the corre- 

 lation of deposits in which moUusks are the only abundant organisms. 

 I trust this serious omission may be remedied before a great while. 



Needless to say aU of the paleontologists who have studied the 

 fossils submitted to them have cooperated in trying to solve the 

 problems of local and regional geologic correlation, and I wish to 

 record my grateful appreciation of their efforts. I wish also to thank 

 my friend, Dr. T. W. Stanton, of the United States Geological Survey, 

 for much advice and kindly criticism. 



BIOLOGIC CHARACTER OF THE SEDIMENTARY FORMATIONS IN 



PANAALA.. 



Eocene. 



The only geologic formation of Eocene age definitely recognized 

 in Panama is exposed near Tonosi, Los Santos Province. At station 



547 



