Another ID please!

[Zerc]

I saw these on one of my rocks today. Looks like a hard tube shell growing along the side of the rock. They seem to grow in a circular pattern. The shell is very hard (I poked it with a wooden spoon to see if it was soft). They are alive, i saw the end of one of them open a little and spit out some waste for 5 or 10 seconds. I took one pic with each of them in focus, but I circled both shells in both pictures. Any Ideas?

 

[Zerc]

Ok I got some more info! I found a 3rd one this evening and I noticed that two of these things had 4 inch "spider webs" going out of their openings today, and the cap was lowered with a little head sticking out that was either spinning or reeling in the web. I believe the one that did not have a web only did not because today one of my anemones decided to sit on it... I have noticed these webs before, but never saw where they were coming from. What kind of worm has a tube almost 1/4" thick, a few inches long, and spins a web?

 

[user 26995]

they are vermetid snails.
most of the time they are burried in a hole or colony of zoas or someplace you cant see their shells

 

[Zerc]

Wow, yuck... I think some super glue will fix those! Thanks for the help again!

 

[user 26995]

Yeah they can be a pest.