Tidepool Tim says,  "This is a flattened worm-like species that we find under rocks at low water.  They are hard to pick up because of their shape.  We usually find a mussel or clamshell to scoop them up with.  These fall into a group called Micruran worms, a special group of nemerteans.  This one looks like a reddish leech or tapeworm.  They have a very transfixing method of movement. Pop them into a petri-dish with a little seawater and the show begins. Great to show on a dissection scope projector.  Kids love it!”