What first link
This one was the first link and they are not worms. How many do you have ? Yoiu will not find these in high numbers 1 or 2. If you have many more,i.e 5, 10 ,20 etc.. them more than likely they are flat worms. Try for a new pic some we are sure

. If it is a Aplysid, it will have two "rabbit like ears"
http://www.seaslugforum.net/aplysaga.htm
or this one, red flat worms
http://www.seaslugforum.net/display....tworm2&id=5836 