A slipper limpet, which delights in the Latin name Crepidula fornicata, begins life as a male and becomes a female when it ceases peregrinating and settles on a rock; another male lands on it, and gradually it, too, turns female; a third male lands, and so on, until there is a tower of ten or more slipper limpets, the bottom ones being female, the top ones male.
