This is quite an attractive flatworm, with its white rolling margin and central white stripe on a gold-flecked background.  It’s small (about 1′ or 25 mm) and can easily be mistaken for a really tiny White-margin nudibranch — until it moves, undulating acoss the rocks at a speed no glossodoris could possibly replicate. Found in about six feet (2 metres) of water in an exposed area of rubble and algae/sponge-covered rock in North Kihei.  For more information, photos and links check out John Hoover’s Hawaii Flatworm page.