TAB. II. 



Fig. 



1, la. Pecten lens, p. 11. 



2, 2#. Hinnites velatus. p. 14. 



3, 3 a. ,, tegulatus, p. 14. 



4, Plicatula tuberculosa, j. 15. 



5, fistulosa, p. 15. 



6, Qa. Avicula costata,jy. 15. 



7, 7 a, 6. echinata.jo. 16- 



Pteroperna costatula, young of, showing the costated 

 surface, p. 18. 



9. Gervillia crassicosta, j. 23. 



10. Pteroperna emarginata, />. 19. 



11. 11 a. pygmaea, p. 19. 



12. 12. Gervillia ovata, p. 22. 



1 3 . Pteroperna costatula, p . 1 8 . 



13 a. Interior of ditto, showing muscular impression and 



hinge area, p. 18. 



14. 14 a, 6. Gervillia monotis, jo. 22. 



15. Bathonica, p. 21. 



