A whorl (/wɜːrl/ or /wɔːrl/) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs).[1][2]
For mollusc whorls, the body whorl in a mollusc shell is the most recently formed whorl of a spiral shell, terminating in the aperture.
{{cite journal}}
: CS1 maint: multiple names: authors list (link)