pst-shell is a PSTricks related package to draw seashells in 3D
view: Argonauta, Epiteonium, Lyria, Turritella, Tonna,
Achatina, Oxystele, Conus, Ammonite, Codakia, Escalaria,
Helcion, Natalina, Planorbis, and Nautilus, all with different
parameters. pst-shell needs pst-solides3d and an up-to-date
PSTricks, which should be part of your local TeX installation,
otherwise get it from a CTAN server.
