Fossil IDs in Burrow

[Gbreeder]

Hello everyone! This is my first post on the entire forum, I read the rules, the ruler thing doesn't work out too well since these are in a burrow - which I don't really want destroyed. 

I can try getting clearer images if anyone wants. Tried my best with these.

Some people on another site mentioned one of these could be a worm in the Serpulidae family, another was mentioned as possibly being a barnacle. 

I live in Dayton, PA - this rock was found in a hill which was dug into for a pool few years ago. Have been looking around the area for interesting rocks and happened upon this, put it into a pile with other interesting rocks.

Finally got around to brushing dirt off them and noticed the small white bits on this one.

Any help would be appreciated !

[jpc]

the last photo certainly looks like a serpulid worm case.  And it looks like you've got rock-boring clams in there as well.  

[Lone Hunter]

In first large image on left side it does look like barnacles to me.

[Gbreeder]

Should I break larger rocks that I found near this piece?

Also have some iron concretions from the same general area. Some of them have small white bits - haven't noticed any impressions. 

Should I attempt to break / chisel them? They are pretty hard being a form of iron and all.

If I can find more fossils in the same spot, that would be nice.

[Rockwood]

42 minutes ago, Gbreeder said:

these are in a burrow

I doubt this is a burrow. Can you explain why you call it such ?

[Gbreeder]

Just now, Rockwood said:

I doubt this is a burrow. Can you explain why you call it such ?

Someone on another site mentioned worms could have made the burrow - though its looking more like rock-boring clams are the culprit.

[Rockwood]

36 minutes ago, Gbreeder said:

Someone on another site mentioned worms could have made the burrow - though its looking more like rock-boring clams are the culprit.

Okay. How bivalves happened to be boring rock in a burrow was my issue.