Land or aquatic mollusk having a foot and head, which retract into a spiral shell made of a single piece.
morphology of a univalve shell
Protruding line on the whorl of the shell parallel to the suture line.
Each of the turns around the apex, except the last; its diameter grows.
Tubular extension of the opening of the last complete turn allowing water to circulate.
Inner wall of the opening made by the last complete turn of the shell, opposite the outer lip.
Small protuberance located along the columella.
Protruding line on the whorl of the shell parallel to the columella.
Outer wall of the opening made by the last complete turn of the shell, opposite the inner lip.
Orifice of the last complete turn allowing the head and foot of the mollusk to exit; it also withdraws into its shell through this opening.
Line marking off the successive whorls of the shell.
Solid axis of the shell that can be solid or hollow; the whorls turn around it.
First complete turn of the shell formed at the larval stage.
Crown from which the shell grows.