Looks to me like it might be either an H. magnifica, or an H.crispa like Gabriella said. Cant be sure w/o a pic of the base....but the fact the seller called it an Long Tentacled Anemone, leads me to think its probably H.crispa.
They're also called LTA's, but they are different from the Macrodactlya doreensis that are most usually LTA's. They arent as hardy as M.doreensis, but do bury their foot in substrate. It will host most types of clowns.
Needs excellent water quality and likes strong light...not too fond of heavy direct current.
edit...nice call Gabby
Nick