This is apparently a relatively common flatworm, perhaps because it is easily found by tide-poolers and shallow snorkelers. It is fairly round and can reach up to 70 mm or 3″. Both individuals were found at Makena Landing in approximately 6 ft or 2 metres of water in an area of surge and tossed, algae and sponge covered rocks. For more information check out John Hoover’s Hawaiian Flatworms page.