Chambered Nautilus, Nautilus pompilius
Boggling to scientists, the Chambered Nautilus' interior shell structure exhibits a nearly perfect equiangular spiral. Native to the South Pacific, these creatures are related to squids & octopi. They are the only Cephalopod to have a shell and use their gas filed compartments inside their shell to change their depth like a submarine. Notecard measures 4 1/2" x 5 1/2," includes an envelope, and comes in a clear plastic sleeve.