PLATE XXV 



PAGE 



Figs. 1-5. NUCULA BELLISTRIATA (Conrad) 227 



1. Right valve. X 1%. 



2. Right valve, showing concentric striae and strong varices of growth. 



xiy 2 . 



3. Left valve. X 2. 



Romney formation, Hamilton member, Evitts Creek. 



4. Interior of right valve, showing muscular scars. X 1%. 



5. Cardinal view of same. X l 1 /^. 



Romney formation, Hamilton member, Western Maryland. 



Figs. 6-8. NUCULA LIRATA (Conrad) 229 



6. Left valve, distorted somewhat about the beak. Romney formation, 



Hamilton member, Evitts Creek. 



7. Right valve. 



8. Enlarged surface showing strong concentric undulations and fine 



radiating striae. 



Hamilton formation, New York. 



Figs. 9, 10. NUCULA LIKATA (Conrad) (?) 229 



9. Interior of left valve, showing muscular scars, pallial line and 



hinge crenulations. X 1%. 



10. Cardinal view of same specimen, showing muscular scars and 

 hinge crenulations. X l 1 ^. 



Romney formation, Hamilton member, Western Maryland. 



Figs. 11-16. NUCULA VARICOSA Hall 230 



11, 12. Right and left valves. X l 1 ^. 



13. Left valve, showing concentric striae and varices of growth. X l 1 ^. 



14. Enlargement from same, showing the character of the concentric 



striae and varices of growth. X 4. 



Romney formation, Hamilton member, Evitts Creek. 

 15, 16. Right and left valves. Hamilton formation, New York. 



Figs. 17-20. NUCULITES OBLOSGATTJS Conrad 231 



17. Left valve showing fine concentric striae. Evitts Creek. 



18. Small left valve also showing fine concentric striae. X 2. Evitts 



Creek. 



19. Interior of right valve, showing crenulated hinge and impression 



of clavicular ridge. National Road, northeast of Cumberland. 



20. Interior of right valve elongated by pressure. Hill in West Vir- 



ginia, 3 miles south of Cumberland. 

 Romney formation. Hamilton member. 



108 



