peristome

peristome [per-uh-stohm] ExamplesWord Origin noun

1. Botany. 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.
2. Zoology. any of various structures or sets of parts that surround or form the walls of a mouth or mouthlike opening.

Origin of peristome From the New Latin word peristoma, dating back to 1790–1800. See peri-, -stome Related formsper·i·sto·mal, per·i·sto·mat·ic [per-uh-stuh-mat-ik] /ˌpɛr ə stəˈmæt ɪk/, per·i·sto·mi·al, adjective Examples from the Web for peristome Historical Examples of peristome

Peristome strongly constricted, one-third as broad as the shell, with nine large ovate lamellar, slightly convergent feet.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index

Ernst Haeckel

Peristome small, constricted, scarcely one-fourth as broad as the shell, with twelve to fifteen short triangular vertical feet.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index

Ernst Haeckel

Peristome constricted, with six divergent cylindrical, irregularly curved feet, twice to three times as long as the shell.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index

Ernst Haeckel

The peristome bears a double marginal ring of divergent conical spines, the upper being directed upwards, the lower downwards.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index

Ernst Haeckel

Peristome with a coronet of fifteen to twenty parallel and vertical triangular lamellar feet, nearly as long as the thorax.

Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, Second Part: Subclass Osculosa; Index

Ernst Haeckel

British Dictionary definitions for peristome peristome noun

1. a fringe of pointed teeth surrounding the opening of a moss capsule
2. any of various parts surrounding the mouth of invertebrates, such as echinoderms and earthworms, and of protozoans

Derived Formsperistomal or peristomial, adjectiveWord Origin for peristome C18: from New Latin peristoma, from peri- + Greek stoma mouth peristome in Science peristome [pĕr′ĭ-stōm′]

1. A fringe of toothlike appendages surrounding the mouth of the spore capsule of some mosses. The teeth unfold under damp conditions and curl up under dry conditions to disperse spores gradually.
2. The area or parts around the mouth in certain invertebrates, such as the echinoderms.