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It is Marionia sp. 13 in IPN page 342, let me quote the description: "This species has large secondary gill branches with transverse lines across the notum. The body color is light brown with a uniform pattern of undulating darker brown longitudinal bands. The velar processes are slightly branched."
I do not see any longitudinal lines at the specimen in IPN, I guess they meant transverse lines.
Gosliner, Terrence M., David W. Behrens & Ángel Valdés. 2008. Indo-Pacific Nudibranchs and Sea Slugs. Sea Challengers Natural History Books.
Gig Harbor, Washington. 426pp.
How to cite:
Köhler, E. (2016), published 3 December 2016, Marionia sp. 11 Genus: Vayssière, 1877
available from https://www.Philippine-Sea-Slugs.com/Nudibranchia/Dexiarchia/Marionia_sp_11.htm