http://www.angelfire.com/mi/sharkcage69/page26.html
http://www.imicom.or.jp/~bolland/halg_sp3.html
http://www.seaslugforum.net/showall/halgsp5
http://www.cosmos.ne.jp/~breach/slug%20full%202/nudi%20full57.html
http://www.cosmos.ne.jp/~breach/slug%20full%202/nudi%20full59.html
http://www.cosmos.ne.jp/~breach/slug%20full%205/nudi%20full129.html
http://www.columbia.edu/~la202/uid-LAMD07.html
http://www2.gateway.ne.jp/~coon/slug-47.htm
http://www.ne.jp/asahi/kappa-kuri/miyamoto/OSEHOO/umiushi180.html
http://www.umiushi.info/photo_species/photo_splist_eng.php?sopt=0&loc=0000
http://www.medslugs.de/E/Pac-W/Halgerda_sp_01/Selection.htm
http://www.medslugs.de/E/Ind-NW/Halgerda_sp_03/Selection.htm
http://www.seaslugforum.net/showall/halgsp8
http://www.cosmos.ne.jp/~ononini/seaslug_addenda4/add4_07.html
http://www.underwaterkwaj.com/nudi/cryptobranchs/e209.htm
http://www.underwaterkwaj.com/nudi/cryptobranchs/e212.htm
http://www.scuba-equipment-usa.com/marine/SEP05/Purple_Lined_Halgerda(Halgerda_sp).html
http://www.nudipixel.net/species/halgerda_sp/
http://marliwakeling.jalbum.net/Nudibranchs/slides/Halgerda sp.html
http://www.medslugs.de/E/Pac-NW/Halgerda_sp_05/Selection.htm
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=1152
http://slugsite.us/bow2007/nudwk816.htm
http://rfbolland.com/okislugs/halg_sp1.html
http://www.Philippine-Sea-Slugs.com/Nudibranchia/Euctenidiacea/Halgerda_sp_02.htm
http://www.medslugs.de/E/Pac-W/Halgerda_sp_06/Selection.htm
http://www.medslugs.de/E/Ind-SW/Halgerda_sp_08/Selection.htm
http://www.medslugs.de/E/Ind-SW/Halgerda_sp_09/Selection.htm
http://slugsite.us/bow2007/nudwk959.htm
http://slugsite.us/bow2007/nudwk982.htm
http://www.medslugs.de/E/Ind-SW/Halgerda_sp_10/Selection.htm
https://www.vibrantsea.net/halgerda8840_anilao2019.htm
https://www.vibrantsea.net/halgerda8849_anilao2019.htm
http://slugsite.us/bow2007/nudwk1200.htm