A question for the scholars of our list and the inherently curious. I have
and have sliced many shells from apex to 'toe'. Until today, all interiors
are relatively smooth. Gone are the spines of the murex, 'teeth' of cowries.
But today, upon slicing a helmet shell, lo and behold, in the interior
spaces, 'teeth', flanges, even the knobby (once) exterior. Any thoughts.

Ron in the 1/2 inch hail in Olympia.