Sandro,
 
Thanks for the question on the curled chitons, I am sure more than a few of us
have had that problem.  Glenn and Laura, thanks for the expert advise.  I have
been a bit afraid to soak them. I tried and had only slight luck with those that
are still a bit flexible by drying them out a bit in the microwave.  I put a
weight on the chiton to straighten it out and just use 3 second bursts and
always feel the critter to make sure it doesn't start to cook.  It seemed to
help a little but the curl still wants to return.  The real answer is to prepare
the chiton yourself or get it from someone who knows what they are doing.  If in
doubt see Glenn and Laura's chiton page - it has full details on preparation and
display.  My curled chitons are now tied to a microscope slide (as you recommend
for wet display) and I'll check them in a year to see how they are doing.
 
Tom Eichhorst in New Mexico, USA