Bull. U. vS. B. F., 1919-20. 



Pl.^te VIII. 



Fig. 1- — Lake Pepin, an expansion of the Mississippi River between Wisconsin and Minnesota, 

 a favorable habitat for fresh-water mussels. 



Til. : — X.irth Fi.rk of Kentucky River, near Jackson. Kv.. with sand bottdin and contlitions unfavc-r.il li 11 imi^-^cU 



( Danjiliulo. > 



-Tea Table shoals, another portion of the Kentucky River; the shores indicate stability, tli' 

 niuderately dcei>, and the environment is favorable for mussels. 



c water IS 



