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



Fig. 224. — Oyster boat dredging up mussels in Narragansctt Bay. 



Fig. 225. — Modified coal screen used for cleaning and sti arating mussels 



Fig. 226.— Revolving screen cylinder in tank of water used for final cleansing 

 of mussels. Wire baskets for holding mussels are shown at right. 



