TAB. 11. 



Fig. 



1, 1 a. Pecten lens, p. 11. 



2, 2 a. Hinnites velatus. p. 14. 



3, 3 a. „ tegulatus, p. 14. 



4, Plicatula tuberculosa, p. 15. 



5, „ fistulosa, p. 15. 



6, 6 a. Avicula costata, p. 15. 



7, la, b. „ ecbinata, p. 16- 



8, Pteroperna costatula, young of, showing the costated 



surface, /;. 18. 



9, Gervillia crassicosta, p. 23. 



10, Pteroperna emarginata, p. 19. 



11, 11a. „ pygrnsea, p. 19. 



12, 12 a. Gervillia ovata,/;. 22. 



13, Pteroperna costatula, p. 18. 



13 a. Interior of ditto, showing muscular impression and 



hinge area, p. 18. 



14, \4?a,b. Gervillia monotis, p. 22. 



15, ,, Bathonica, p. 21. 



