- What an oyster with maternal instincts eventually becomes? - The hard pearly internal layer of several kinds of
shells, esp. of pearl oysters, river mussels, and the abalone shells;
nacre. See Pearl.
- A form of the larva of certain Discophora in a state of
development succeeding the scyphistoma. The body of the strobila
becomes elongated, and subdivides transversely into a series of lobate
segments which eventually become ephyrae, or young medusae. - A mature tapeworm.