Shell: shell of a mollusk.
Spires: rolled part of the shell.
Body whorl: last whorl.
Siphonal canal: tubular part of the shell, used for siphoning.
Siphonal fasciole: spiral band on the siphonal canal.
Labrum: lip of the shell.
Columella fold: edge of the siphonal canal.
Operculum: calcified structure used to close a shellfish's shell.
Parietal lip: inner edge of the shell aperture.
Outer lip: outer edge of the shell aperture.
Spiral rib: part of the shellfish rolled onto itself.
Varix: axial structure on the rounded top.
Whorl: structure of the carapace.
Suture: joint between to whorls of the shell.
Axial rib: the axial part of a shell.
Apex: the point of a shell.