hi id this please

[pete_ra]

if u want a pic i can get it, but i have many of these growing on my rock. There look normal and harmless. There are little white branch like twigs sticking of the rock, very small, about 1/3 inch tall at most.

[on_fire_8]

sounds like a small tube worm. Benificial detrivore.

[sinasster]

I seen something like that once, I was told it was calcium deposits.

fact or fiction I do not know.

[surgeon67]

one other possibility is a sessile snail. Is ther mucus coming out the end in fine strands?

[steve1s]

Sounds like a common calcerous polychaete>> Spirorbidae (http://www.horta.uac.pt/Species/Annelida/Spirorbidae_sp/Spirorbidae_sp.htm)

or as surgeon68 suggested>> Vermetid Snail (http://www.globaldialog.com/~jrice/invert_page/vermetid.htm)

Cheers
Steve

[frizzbee30]

Sounds like bryozoans or hydroids.I have similar on my live rock.Hydroid colonys are fascinating in that each polyp is very specific in function. They dont cause any harm and are really rather attractive...if u have a good magnifying glass :D