PLATE 11. 



PAQK 



Fig 13. RANELLA MATHKWSONII Natural size. 



Fig. 14. CUMA BIPLICATA. Natural size. 



Fig. 15. ANCILLARIA FISHII. Natural size. 



Fig. 16. COLUMBELLA KICHTHOFKNI. Magnified. 10 



Fig 17. NEVERITA CALLOSA. Natural size. 



View of the base. 



17 a. Side view to show the form of the callus. 



17 b. Top view. 



Fig. 18. CANOKLI.ARIA (EucLiA) TRITONIDEA. Natural size. 

 Fig. 19. (-. (E) VETUSTA. 12 



Magnified to nearly twice natural length. 

 Fj^ 20. BITTUIM ASPERUM. Magnified. 



Fig. 21. M ELAN i A TAYLORI. Natural size. 



Fig. 22. LITHASIA ANTIQUA. Magnified. 



Fig. 23. LITTORINA KKMONDII. Magnified. 



23, 23 n. Two extreme forms of a variable species. 



Fig. 24. TURRITELLA HoFFMANx'n. Natural size. 14 



Fig. 25. TROCHITA FILOSA. Natural size. 15 



25 a. Side view. 



