PELECYPODA OF THE 



ST. MAURICE AND CLAIBORNE STAGEvS 



G. D. HARRIS 



In a general way the Eocene series of the Gulf border ma>- 

 \'ery properl}- be subdivided into five stages, — three representing 

 for the most part marine sedimentation ; two palustrine though lo- 

 calh' becoming marine and filled with beautifully preserved mol- 

 lusca. In their natural sequence these stages are : 

 Jackson stage, marine 

 Claiborne stage, lignitic or lacustrine 

 St. Maurice stage, Marine 

 Sabine stage,* lignitic or lacustrine 

 Midway stage, marine 



In the summer of 1895 the writer made a somewhat extended 

 expedition in the Southern States east of the Mississippi, visiting 

 and collecting from such localities as might furnish well preserved 

 basal Eocene fossils. The results of this expedition were com- 

 bined with observations previousl}- made while on the Arkansas 

 and Texas Geological Surveys, and published as Bulletin No. 4 

 (Amer. Pal.) June, 1S96. After another extensive field sea.son 

 in a slightly more southern latitude along the outcropping of the 

 next higher stage, Bulletin No. 9 appeared (June '97) on the 

 Pelecypoda of the Lignitic Stage ; the Gastropoda, Pteropoda 

 and Cephalopoda followed in Maj^ '99 as Bulletin 11. 



*No\v known as the Sabine stage from the river by that name separ- 

 ating Sabine County, Texas and Sabine Parish, L,a. and showing good fossil- 



