Some genera with helicoidal shells are related to these coiled forms, viz.
The rock was singularly striated, the scratches arranged concentrically and in helicoidal curves.
The most interesting application of the helicoidal saw is in the exploitation of quarries.
helicoid hel·i·coid (hěl'ĭ-koid', hē'lĭ-)
Arranged in or having the general shape of a flattened coil or spiral.
Adjective Arranged in or having the approximate shape of a flattened coil or spiral curve.
Noun A surface in the form of a coil or screw. A helicoid is generated mathematically by rotating a plane or twisted curve about an axis at a fixed rate and simultaneously translating it in the direction of the line of axis, also at a fixed rate.