Så 
FEER 
ne 
41 
8, SPHÆRIUM TRANSVERSUM, Say. 
Smithson. Monogr. 
Canada. 
Western New York. 
New Jersey. 
Pennsylvania. 
New Harmony, Indiana. 
Arkansas. 
Alabama. 
Florida. 
Wabash river. 
Cyclas detruncata, Prime. Schuylkill river. 
Cyclas gracilis, Prime. Ohio. 
Cyclas constricta, Anthony. Ohio. (Ex auctore.) 
Sphærtum contractum, Prime. Big Prairie Creek, Alabama. 
Spøhærium contractum, Prime, Mt. Carmel, Illinois. 
10. SPHÆRIUM SECURIS, Prime. 
Smithson. Monogr. 
Canada. 
Maine. 
Massachusetts. 
Rhode Island. 
