Though this flatworm is rarely found, I have come across a few over the past three years.  All seem to be at different stages of development; however, very little is known about cf. Prosthistomid 3. The individual with the more defined line was just under an inch (20 mm) and was found in about 10 ft of water (3 metres) in the surgy back lagoons off Makena Landing, Maui. The worm with far more orange and missing a distinct central line was found in the same area a few months later. The worm that seems to combine the features of both was found a couple of years later, in the same area and was approximately 40 mm.  They are fast moving worms able to thin out and sweep into a hole in seconds. It’s really hard to say if these are all examples of cf. Prosthiostomid 3, but I’m going with that for now. I’ve once again relied on John Hoover’s website to justify my claims.