217 St. Maurice and Claibounk Pelecypoda 217 



PLATE 16 



Figure Page 



1-2. Lima harrisiana A\d., X i '4 ; Winn Parish, La 29 



2-3. Pteria linnila Conrad, natural size 29 



Showing hinge, thickening of shell in adult, muscular scars 

 and general outline of the valves. All from 'the Clai- 

 borne "sand". 



8-11. Pinna gravida, i\. s^., natural size 30 



Showing outline, cross-section and surface markings so far as 

 known. From St. Maurice, La. 

 12.13. Surface markings of P. caw<~a:vensis, enlarged ; see next plate. 



