Dr. Ron Shimek says;
"Polyclad Flatworms
Polyclad flatworm are larger animals than those pictured above, and have a branched gut that is often visible inside the animal. The name "polyclad" means "many branches and refers to the many visible branches off of the central part of the gut. These worms may exceed several inches in length, although those seen in aquaria are not generally over a couple of inches long. Polyclads are generally thought to be predatory, often on small worms, crustaceans, but also occasionally in aquaria, snails and clams. "