PLATE II 



Figure 4. Crepidula fornicata. 



5. Crepidula plana. 



6. Crepidula convexa. 



7. Crucibulum striatum. 



(A), young shell. 



(B), showing egg clusters. 



(C), in act of crawhng, 



8. Cemoria noachina. 



(A), ventral view. 



9. Margarita undulata. 



(A), greatly enlarged view of marginal tentacles. 



10. Margarita heUcina. 



(A), enlarged view of snout, with enlarged papillae at end 

 of snout. 



11. Trochus occidentalis. 



