http://www.seaslugforum.net/showall/thorvill
http://rfbolland.com/okislugs/thorvill.html
http://www.medslugs.de/E/Pac-W/Thordisa_villosa/Selection.htm
http://www.nudipixel.net/species/thordisa_villosa/
http://www.medslugs.de/E/Ind/Thordisa_villosa/Selection.htm
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=267
http://www.vibrantsea.net/thordisa2034_anilao2013.htm
http://slugsite.us/bow2007/nudwk1103.htm
https://www.vibrantsea.net/thordisa8084_anilao2019.htm