This nudibranch is quite simply stunning — all photos below are of one smallish individual (4 cm) that I found in the low intertidal/subtidal boundary moving its way through some kelp.  At first I thought this was an orange version of the very similar Dirona albolineata (common names: Frosted, Alabaster and White-lined).  But the lack of a white line on its foot and the all-to-obvious white spots on its mantle and cerata definitely pointed to another species!  Yay!  For more info and photos related to its egg-laying, check out Jackie Hilderling’s Marine Detective blog.