Dunno. I've only collected one sort.
And I've only done it in france. I've never been able to collect enough in England.
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Dr. Shambolic je suis charlie, Tue 16 Jun 2009, 18:40,
archived)
I heard if you smash one up with a hammer all the little bits regrow as snails
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glued eel /questions/questionsyoudliketoask/post1648081, Tue 16 Jun 2009, 18:43,
archived)