TAB. XII. 



Fig. 



1 . Paludina lenta, page 110. 



a. front view, var. a. 



b. front view, var. /3. 



c. back view, young shell. 



2. Paludina tentaculata, p. 111. 



3. Valvata piscinalis, p. 112. 



4. Natica occlusa, p. 146. 



a. back view. 



b. front view. 



5. Natica Groenlandica, />. 146. 



a. back view. 

 #. front view. 



6. Paludestrina pendula, p. 109. 



7. Paludestrina terebellata, jo. 109. 



8. Vermetus intortus, p. 113. 



. solitary specimen adhering to an oyster. 



b. gregarious specimen. 



9. Vermetus Bognoriensis, (?) p. 114. 



10. Lacuna reticulata, p. 122. 



11. Alvania ascaris, p. 99. 



a. var. subulata. 



b. var. brevis. 



c. var. nitida. 



The lines indicate the size of the specimens. 



