Live rock creatures

so I started my saltwater aquarium 2 weeks ago and I have three pieces of live rock. The second day the live rock was in there I saw a crap load of worms 2 big bristle worm. And a lot of little worm like things. All the little ones look they have died off but now I have noticed some other things living on it. Kind of a spitter web looking thing that hase tentacles on it that reach out in the sand . And what appears to maybe be a clam that has grown on one rock. Not really sure that it's a clam,lol. Can someone kinda give me an idea of what things can be living on or in my live rock?? Please help me identify what these might be.

 

Welcome to 3reef,

Sounds like vermetid snails/worms.

 

a couple links I like to reference. Some nice looking rock. Can't really give you particular names on stuff but second pic look like possible zoa not fully open.

After giving another look and zooming in it is not Zoa sorry.






http://www.chucksaddiction.com/hitchhikers.html
http://www.lionfishlair.com/hitchhiker/hitchhiker.shtml

 

Thanx for the help!

 

^That is a common LPS hitch-hiker Montastraea, a stony coral or aka Star Coral.

The bivalves, look like Oysters but they could be clams.