PLATE LXV. 



PAGE 



Fig. 1. Pholas (Thorana) producta Conrad 274 



1. Exterior of left valve. South Carolina. (After Tuomey and 



Holmes.) 



Figs. 2, 3. Barnea (Scobina) arcuata (Conrad) 274 



2. Exterior of right valve. St. Mary's River. 



3. Exterior of right valve. Same locality. 



Figs. 4-9. Martesia ovalis ( Say) 275 



4. Exterior of right valve and broken protoplax. Drum Point. U. S. 



National Museum. (After Dall.) 



5. Exterior of left valve and protoplax. Jones Wharf. 



6. Exterior of right valve. Same locality. 



7. Interior of left valve. Same locality. 



8. Dorsal view showing gaping anterior and umbonal region pro- 



jecting from enveloping tube. 



9. Interior view of protoplax. Same locality. 



Fig. 10. Panopea whitfieldi Dall 276 



10. Exterior of right valve. Plum Point. 



