this website exists no more:
http://www.biology.ucsc.edu/classes/bio161l/NUDI/hchani.html
http://www.seaslugforum.net/showall/hallchan
http://www.medslugs.de/E/Pac-NE/Hallaxa_chani/Selection.htm
http://slugsite.us/bow2007/nudwk1196.htm