I've been trying to find out the identity of this thing for a while. It kind of looks like a tunicate (with inhalant and exhalant siphons) but seems to be living in a tube. The 'tube' has grown longer over the last 6 months and is covered with Cyphastrea. I have seen something similar in the past but it was much smaller and growing on a snail shell. I am so very curious to know what this thing is and really hope someone here can help me ID it.