PLATE LXVIII. 



PAGE 



Figs, la, lb, 2. Mya pkoducta Conrad 283 



la. Interior of left valve. Jones Wharf, 

 lb. Exterior of same valve. 



2. Profile of hinge area of same valve. 



Figs. 3-6. Sphenia dubia (H. C. Lea) 283 



3. Exterior of left valve. Jones Wharf. 



4. Exterior of right valve. Jones Wharf. 



5. Interior of left valve, large specimen. Jones Wharf. 



6. Exterior of right valve, same individual as Fig. 5. 



Figs. 7, 8. Pakamya siibovata Conrad 284 



7. Interior of left valve. Two miles south of Governor Run. 



8. Exterior broken valve. Jones Wharf. 



