Not Part of Moss Capsule: Operculum

Protonema:
- Protonema is the first stage in the development of mosses from spores.
- It is a filamentous, branching structure that emerges from the germinated spore.
- Protonema eventually develops into the leafy gametophyte plant.

Annulus:
- The annulus is a ring of specialized cells found on the sporangium of some mosses.
- It plays a role in the dispersal of spores.
- As the sporangium dries, the annulus contracts and releases spores.

Peristome:
- Peristome is a ring of tooth-like structures surrounding the opening of the moss capsule.
- It regulates the release of spores and helps in their dispersal.
- The structure and arrangement of peristome teeth are important in moss classification.

Theca:
- Theca is the capsule or sporangium of the moss.
- It contains spores produced through meiosis.
- Theca is an essential part of the moss life cycle, as it protects and disperses spores.
Therefore, operculum is not part of the moss capsule. It is a lid-like structure found in some moss capsules that opens to release spores.