the membrane closing the adult shell when the protoconch is broken off.
Compare: caudal joint; caudal fold; caudal septum; caudal spine.
Alternative forms for caudal septum : caudal spine mark, closing membrane.
the membrane closing the adult shell when the protoconch is broken off.
Compare: caudal joint; caudal fold; caudal septum; caudal spine.
Alternative forms for caudal septum : caudal spine mark, closing membrane.