http://rfbolland.com/okislugs/siphnigr.html
http://www.seaslugforum.net/showall/siphnigr
http://www.umiushi.info/photo_species/photo_splist_eng.php?sopt=0&loc=0000
http://www.h.do-up.com/home/takayan/takapage349.htm
http://online.divers.ne.jp/ono/seaslug7/room7-12.html
http://www.medslugs.de/E/Pac-NW/Siphopteron_nigromarginatum/Selection.htm
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=31
http://slugsite.us/bow2007/nudwk1185.htm