little white pods: what are these?

[SeymourJives]

i have discovered several small white pods underneath a piece of live rock. anyone know what these are?

here is a picture

 

[Yellow Eye Tang]

It's been so long since I had my reef tank... but if I'm not mistaken those are a form of sponge. I had them in low light areas of my rock in my old reef. They appeared to cause no problem and actually seemed beneficial. In mine the tips would catch extra food. I wish I could give ya a more professional explanation but I can assure you not to worry about them.