Bull- U. S. B. F., 1921-22. (Doc. 922.) 



204 



205 



FiG. iyS. — The winkle, Neverita duplicate 



Fig. 199.— Valve of a sea mussel which has been perforated by one of the winkles. Neveriia 



duplicate or Lunatiakei 

 Fig. 200. — The winkle, Lunatiakeros. 



Fig. 201.— The oyster drill, i 'rosaipinx an? rev. ami a mussel shell it had perforated. 

 Fir,. 202.— The dog whelk, Purpura lapillu r, and a mussel shell it had perforated. 

 Fig. 203.— Thestarfish, Aslerias f^rbesii, attacking a mussel. 

 Fig. 204. — The conch, Busycon carica. 

 Fig. 205.— The conch, Busycon canali<ulut<!. feeding on a mussel. 



