217 St. Maurice and Ci.aiborne Pelecypoda 217 



PLATE 16 



Figure Page 



1-2. Lima harrisiana A\A., X 1% ; Winn Parish, La 29 



fe-3,']| Pteria limula 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, n, s^., natural size ».. 30 



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

 known. From St. Maurice, L,a. 

 12.13. Surface markings of P. cawcaivensis, enlarged ; see next plate. 



