White "Tube" on rock. ID Please?

[Glasswalker]

Hey, so found this a couple weeks ago, been meaning to post to ask about it.

Friend thought it was a sponge of some kind. I now have 2 of them on the one rock.

Any suggestions on an ID?

It's about 5-10mm long, and conical, with an opening in one end. Anchored on rock.

Any help is greatly appreciated

Thanks in advance!

Pics:

 

[KJ]

Sponge

 

[Roboson]

Yup, tiny pineapple sponge.

 

[Glasswalker]

Awesome! So not harmful at all from what I understand.

Thanks!