Paul & Ross On your comments... " Another option is one of the commercially available aerosol refrigerant sprays (tetrafluoroethane or similar compounds) which are available in small, easy to use cans, and which can bring a tissue sample down to about -50 degrees C in a couple of seconds." Back in the days when automotive Freon was redily avaiable, I used it to collect chitons and limpets. Quick termination of the subject and no prying. Never id get the curling thing quite down.... Leslie ---------------------------------------------------------------------- [log in to unmask] - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ----------------------------------------------------------------------