Thanks, Emilio and Rich, for bring us up to speed on cleaning of landshells.
What a fine explanation, Rich.  I knew there was something that would bleach
out on those ligs, Emilio! And now I remember the green connection. Does
anyone have any speculation about why this should be so, just green lines
that scrape off?  What would be the advantage?
 
Another landshell periostracum question, this one for Rich:
 
Once I got a beautiful big landshell species from you, large ... maybe a
couple of inches ... and brown and extremely glossy and impressive.  I laid
it on a shelf where I was displaying some other landshell species (I may
admire the critters, but don't pretend to know much about them, and am still
somewhere in the curiosity stage of collecting them). It lived happily there
for quite some time, and then one day I found it broken to bits.  Some
pieces were on the floor and some were scattered about on the shelf.  I
blamed my cats, never completely trustworthy where interesting smells might
linger, or my sons, who had never quite accepted the concept that bouncing
balls in the house would get them into trouble every time. Neither cats nor
kids fessed up. And I nursed a grudge over my lost shell until I happened to
mention it to you later and you told me the species was notorious for being
a time bomb...something to do with drying out.  Can you refresh me on this?
(Yes, I apologized to both cats and kids.  The kids were churlish about it,
and added it to an ever-growing list of stuff they unjustly were blamed for.
They think there's a book in it.)
 
Lynn Scheu