peritreme

noun2

1. •
   That part of the integument of an insect surrounding the spiracles.

   • These peritremes lie partially embedded in the fold of skin known as the epistome (a dorsal anterior projection that extends over the mouthparts or ganathosoma) — 2023
2. •
   (no longer used) peristome (edge of the aperture of a shell).

   • CAROCOLLA. Auct. Fam. Colimacea, Lam.—Descr. Orbicular, depressed, with the outer sides of the whorls angulated or keeled, whorls few; peritreme reflected; columella contiguous to the axis — 1842