PLATE VI {confimiecf). 



Fig. 



13. Cytheridea debilis, p. 43. 



Left valve, outside 



14. Cijthere Kostelensis ? p. 28. 



Wa. Left valve, outside 

 14 5. Perfect, dors.ll aspect 



15. Cytherideis ? sp., p. 49. 



Cast of left valve 



16. Cy there TFetherellii, p. 26. 



a. Left valve, outside 

 h. Right valve, hinge-line 



c. Right valve, dorsal aspect 



d. Right valve, posterior aspect 



17. Cy there plicata, p. 32. 



Left valve, outside 



18. Cy there anyulatopora, p. 34. 



Left valve, outside : broken 



19. Cythereis, sp., p. 40. 



Fragment of left valve 



X 25 Colwell Bay. 



I) 



X 25 



Woolwich. 



X 12 New Cross. 



. X 25 



. X 25 



. X 25 



. X 25 



Colwell Bay. 



. X 25 Colwell Bay. 



. X 25 Colwell Bay. 



X 25 Pegwell Bay. 



