this website exists no more:
http://www.biology.ucsc.edu/classes/bio161l/NUDI/dorissls.html
http://www.seaslugforum.net/showall/heinsdor
http://www.seaslugforum.net/showall/dorisp1
http://www.medslugs.de/E/Ind-SW/Doris_sp_01/Selection.htm
http://www.seaslugforum.net/showall/dorisp3
http://www.seaslugforum.net/showall/dorisp4
http://www.seaslugforum.net/showall/dorisp5
http://www.seaslugforum.net/showall/dorisp6
http://www.nudibranch.com.au/pages/doris.htm
http://www.seaslugforum.net/showall/dorisp8
http://www.seaslugforum.net/showall/dorisp9
http://www.seaslugforum.net/showall/dorisp11
http://www.cosmos.ne.jp/~breach/slug%20full%204/nudi%20full100.html
http://www.opwall.com/opisthobranchs.htm
http://www.sea-slug.com/species/umiusi228.htm
http://www.umiushi.info/photo_species/photo_splist_eng.php?sopt=0&loc=0000
http://slugsite.us/bow2007/nudwk602.htm
http://www.underwaterkwaj.com/nudi/cryptobranchs/e376.htm
http://www.underwaterkwaj.com/nudi/hawaii/h162.htm
http://www.sea-slug.com/species/umiusi332.htm
http://rfbolland.com/okislugs/dori_sp1.html
http://www.seaslugsofhawaii.com/species/Doris-sp1-a.html
http://www.seaslugsofhawaii.com/species/Doris-sp2-a.html
http://www.medslugs.de/E/Atl-SE/Doris_sp_04/Selection.htm
http://www.nudipixel.net/species/doris_sp/
http://www.Philippine-Sea-Slugs.com/Nudibranchia/Euctenidiacea/Doris_sp_01.htm
http://www.Philippine-Sea-Slugs.com/Nudibranchia/Euctenidiacea/Doris_sp_02.htm
http://www.dragonmouse.com.au/diving/nudibase.php?action=nudidetail&id=156
http://www.medslugs.de/E/Pac-W/Doris_sp_05/Selection.htm
http://www.medslugs.de/E/Ind-NW/Doris_sp_06/Selection.htm
http://www.medslugs.de/E/Pac-W/Doris_sp_07/Selection.htm
http://www.medslugs.de/E/Pac-SW/Doris_sp_08/Selection.htm