Bull. U. S. B. F., rn7-18. 



Plate I. 



Lake Pepin mucket, female, Lampsilis lutenla (Lamarck) . 

 Yellow sand-shell. LainpsiUa nnodontoules (Lea). 

 Common river mucket, Lampsilis Ugatuentina (Lamarck). 



A.HDBnSCo Bahimiirp. 



