Click the thumbnail photos to enhance!
Pretty similar are:
Halgerda dalanghita Fahey & Gosliner, 1999 which lacks the papillae and differs by the "Halgerda" gills, and by straight ridges.
Sclerodoris sp. 07 Genus: Eliot, 1904 which differs by excavations or 'pits' near the mantle margin, and lacks the whitish papillae .