http://www.ozemail.com.au/~glaskin/class.htm
http://www.scuba-equipment-usa.com/marine/NOV04/Hairy_Thordisa(Thordisa_verrucosa).html
http://www.nudipixel.net/species/thordisa_verrucosa/
http://www.daveharasti.com/nelsonbay/seaslugs/pagefour.htm