stuckinfla id'd it correctly, try searching for calliactis anemone. There appears to be a few different species. They have a symbiotic relationship with dardanus sp's hermit crabs.
You may be able to keep it alive on meaty foods, but without the hermit im not to sure how long it will live.
If you bought a dardanus hermit it may "move" these anemones to its own shell. But thats a long shot and they are not reef safe, I had one for about a month and one day it went on a fragging spree. I now have xenia growing all over my tank... needless to say I took it back to the lfs and learned another lesson.
The anemones themselves seemed to love frozen brine.