16 Field Museum of Natural History — Geology, Vol. IV. 



PELECYPODS 



Exogyra costata Say. 

 Gryphceostrcea vomer Morton. 

 Ostraa denticulifera Conrad. 



ACKNOWLEDGMENTS 



The publications of P. M. Duncan and E. Desor have been freely 

 drawn upon for the generic descriptions here used, but as they have 

 been rearranged and adapted more or less they have not been treated 

 as quotations. 



President John GofE of the Chickasaw Female College, Pontotoc, 

 Mississippi, gave the writer valuable information as to localities in 

 the field and also later furnished specimens which materially aided 

 in the preparation of this paper. 



