- The free-swimming, hat-shaped larva of certain nemertean worms. This has no similarity to its moms and dad, and also the younger worm develops with its interior.
- A generic title provided to the larvæ of rhynchocœle tur-bellarians, or nemertean worms, under the effect that they're distinct animals.
- In conchology, a genus of false limpets regarding the family Acmæidæ.
- [lowercase] In botany, a hemispherical apothecium in certain lichens.