Beeba - toss up a pic if you can - I'd love to see it, and see if I have anything that resembles it in a few books.
Blue Baron - I'm glad you brought that up. It seems that some folks experience that. Do you happen to have a sandbed? Just curious. I thought I read somewhere long ago that they have a hard time "righting" themselves on the sand, but I'm not sure how true that is. I haven't had a problem with turbos falling on their backs (at least that I've seen), so I can't compare to a BB system.
fishcrazee - thanks for posting! Definately the cone shaped operculum pictured there...great pics. Did you notice one zoo disappearing at a time, or an all around "closing up" of the zoos? How did you finally find it?