The animal figured below is the only specimen of this species I found in Hawaii. It was under a rock at a depth of about 10m at Ewa, Oahu, on 12 December 1985. We have seen the same species in the Marshall Islands. Its deeply pitted surface closely resembles that of a sponge. Gosliner et al (2008) show it as Sclerodoris sp. 2.
Links:
Sea
Slugs of Hawaii
Marshall Islands Sea Slugs
Created 20 April 2009