1.Previous
3.Next

gastropod shell has three major layers secreted by the mantle. The calcareous central layer, ostracum, is typically made of calcium carbonate (CaCO₃) precipitated into an organic matrix known as conchiolin. The outermost layer is the periostracum which is resistant to abrasion and provides most shell coloration. The body of the snail contacts the innermost smooth layer that

1.Previous
3.Next