Cyclinella
Cyclinella is a genus of bivalves belonging to the family Veneridae. The species of this genus are found in Japan and America. Species:

Cyclinella beteyensis 
Cyclinella falconensis 
Cyclinella harrisi 
Cyclinella jadisi 
Cyclinella producta 
Cyclinella subquadrata 
Cyclinella tenuis

References

Veneridae
Bivalve genera