Hi Ron,

In many of the species which produce pronounced varices, and also form
"sculptured" apertures, parietal walls or columellas, as the snail grows, these
features become "internal". Also I have noticed in Murex and Guildfordia,
notches in the spines attached to the preceding whorl opposing new areas of
growth...seems the snail removes these hindrances as part of the natural growth
process.

Ken


[log in to unmask] wrote:

> 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.