# Fasciole > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Fasciole > Markdown URL: https://mediated.wiki/source/Fasciole.md > Source: https://en.wikipedia.org/wiki/Fasciole > Source revision: 1264344127 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{short description|Feature of mollusk shell anatomy}} {{single source|date=December 2024}} thumb|Shell of ''Africotriton carinapex'', showing the fasciole (in white) around the aperture A '''fasciole''' in [mollusk](/source/mollusk)s refers to a band or ribbon-like structure that is often seen as a flattened, slightly depressed area on the [shell](/source/Mollusc_shell), formed by the successive growth lines on the edges of a canal. It is typically found on the surface of the shell near the [siphonal canal](/source/siphonal_canal) or around the [aperture](/source/Aperture_(mollusc)). The fasciole can play a role in the shell's overall structure and appearance. In some species, it might help in identifying the shell or understanding its functional morphology. The term "'''anal fasciole'''" was proposed by [W.H. Dall](/source/William_Healey_Dall) in 1885 to describe the raised ring or band that marks the track of the notch, a prominent feature in the sculpture of some [gastropod](/source/Gastropoda) shells. This structure is particularly notable in turban snails (family [Turbinidae](/source/Turbinidae)). The notch serves to allow waste matter to escape from the anus without contaminating the water flowing to the gills. The anal fasciole is often well-defined and can vary in size and prominence among different species. The term "'''siphonal fasciole'''", named by [Theodore Gill](/source/Theodore_Gill), bears a somewhat similar relation to the anterior end of the [siphonal canal](/source/siphonal_canal), but is generally less distinctly marked off from the rest of the surface. The notch itself is a break or irregularity in the peristome, indicating the position of the siphon. The term "'''anal notch'''" is used to distinguish it from the "'''siphonal notch'''".[https://biodiversitylibrary.org/page/7306317 Dall, W. H. (1885). New or specially interesting shells of the Point Barrow Expedition. Proceedings of the United States National Museum. 7(460): 523-526.] {{source-attribution}} ==References== {{reflist}} Category:Gastropod anatomy --- Adapted from the Wikipedia article [Fasciole](https://en.wikipedia.org/wiki/Fasciole) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Fasciole?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.