"I would say it is possibly Phyllidiella pustulosa, although this is a somewhat problematic variation. The lighter rhinophores and arrangement of black valleys around the pink "hills" are somewhat different from the more typical P. pustulosa. It sort of leans toward photo no. 6 below, which I'm guessing is a form of Phyllidiella hageni. I keep one kind of like this separate as Phyllidiella sp. on the Marshall Islands nudibranch site at http://www.underwaterkwaj.com/nudi/porostomes/e446.htm. "