Nautilus


 * [[image:http://upload.wikimedia.org/wikipedia/commons/0/08/NautilusCutawayLogarithmicSpiral.jpg width="498" height="375" caption="Nautilus Cutaway Spiral Shell"]] || Internally, the shell divides into camerae (chambers)

As the nautilus matures it creates new, larger camerae, and moves its growing body into the larger space, sealing the vacated chamber with a new septum. ||