PLATE LXIX. 



PAGE 



Figs. 1-3. Mesodesma mariana n. sp 285 



1. Exterior of right valve. Cove Point. 



2. Interior of right valve. Same locality. 



3. Interior of left valve. Same locality. 



Figs. 4-6. Ebvilia planata Dall 285 



4. Interior of left valve. Church Hill. 



5. Interior of right valve. Same locality. 



6. Exterior of left valve. Same locality. 



Figs. 7-9. Mactea clatheodon Lea 286 



7. Interior of left valve. Cove Point. 



8. Exterior of left valve. Same locality. 



9. Interior of right valve. Same locality. 



Fig. 10. Spisula (Hemimactea) delumbis (Conrad) 286 



10. Interior of right valve. Suffolk, Va. 96 mm. (After Dall.) 



X 5/6 



Fig. 11. Spisula (Hemimactea) maeylandica Dall 287 



11. Interior of right valve. 92 mm. (After Dall.) X % 



Figs. 12, 13. Spisula (Hemimactea) cuetidens Dall... 288 



12. Outline of young shell traced from incremental lines on broken 



larger valve. 35 mm. (After Dall.) x 5/6 



13. Hinge-plate of right valve: a. dorsal and e, ventral anterior 



laminae; b, anterior arm of cardinal tooth; c, ligament scar, 

 without septum below it; d and f, posterior laminae. 44 mm. 

 (After Dall.) 



