- the one or two circles of small, pointed, toothlike appendages around the orifice of a capsule or urn of mosses, appearing when the lid is removed.
- any of various structures or sets of parts that surround or form the walls of a mouth or mouthlike opening.
- a fringe of pointed teeth surrounding the opening of a moss capsule
- any of various parts surrounding the mouth of invertebrates, such as echinoderms and earthworms, and of protozoans
