http://www.habitas.org.uk/marinelife/species.asp?item=W14740
this website exists no more:
http://www.biology.ucsc.edu/classes/bio161l/NUDI/cviridis.html
http://www.asterisk.no/~emil/nudibranchia/cuthona_viridis.htm
http://www.sea-slug.com/species/umiusi191.htm
http://www.seaslugforum.net/showall/cuthviri
http://www.nudibranch.org/Scottish%20Nudibranchs/trinchesia-viridis.html
http://www.flickr.com/photos/a_semenov/3651121190/
http://www.flickr.com/photos/a_semenov/3650319207/
http://www.umiushi-zukan.com/eng/list_pic.php?ssw=g&kind_id=1256
http://www.medslugs.de/E/Atl-NW/Tenellia_viridis/Selection.htm