topics: |  zoology | picture-book

Nautilus: the shell is mostly hollow air chambers that provide floatation -
	each chamber is sealed off from the center outwards as the organism
	grows.
Photographs and text examine different types of shells, including seashells,
eggshells, and fossil shells, focusing on such aspects as how shells
camouflage themselves and how they may be collected.

{Activities for children, including how to sew a snail:
http://www.lamer.lsu.edu/classroom/seascope/folios/snail_folio.pdf)