Class pelecypoda [Bivalvia or Lemellibranchiata]
Pelekus=hatchet podos=foot lamella=plate branchia=gill
It is the second largest class of molluscs
Exclusively aquatic; mostly marine, some fresh water
Body laterally compressed
Body is covered with a mantle formed of two folds (right&left ) attached dorsally to the body.
Radula is absent
Feeding is by filtration
Sexes are separate