http://www.seaslugforum.net/showall/siphmich
http://www.medslugs.de/E/Ind-SW/Siphopteron_michaeli/Selection.htm
http://www.gastropods.com/0/Shell_50150.html
http://seaslugs.free.fr/nudibranche/a_sipho_michaeli.htm
http://slugsite.us/bow2007/nudwk731.htm