some molluscs the mantle cavity is a brood chamber, and in 头足纲 and some bivalves such as s, it is a .在多类物种中，牠们的外套膜的上皮细胞都能分泌出碳酸钙及，并形成软体动物的外壳。而在，由于其外壳基本上已退化，其外套膜成为了动物的背部表面。The mantle is highly muscular. In cephalopods the contraction of the mantle is use