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The experts have no consens whether Lobiger viridis Pease, 1863 is a synonym of Lobiger souverbii P. Fischer, 1856 or not. There is the consens, that both species might have the same colour variants (with blue lines or without), some scientists (Terrence M. Gosliner, William B. Rudman, Kathe R. Jensen, et al.) see Lobiger viridis as a species of the tropical Indo-Pacific and Lobiger souverbii as a species of the tropical Western Atlantic Ocean and of the Eastern Pacific Ocean, Dr. Richard C. Willan sees them as one world-wide species.
All recent DNA based reseaches on other families and genera have shown, that those species with a suspected world wide distribution often turned out to be a complex of distinct species, I guess L. viridis is also distinct.
A picture of the unrolled parapodial tentacles and more informations on Lobiger viridis are at Bill Rudman's Sea-Slug Forum!