Actinoporus elegans
Arachnanthus nocturnus
Bartholomea annulata
Bartholomea cf. lucida
Condylactis gigantea
Condylactis passiflora
Epicystis crucifer
Lebrunia coralligens
Lebrunia danae
Stichodactyla helianthus
Viatrix globulifera
Those are all the anemones I could find that are found off the coast of Florida, but there are probably more. Yours could be any one of those. Can you get a pic of it?
Just a note: You should never release any animal back into the water after it touches your tank. It could potentially introduce foreign animals and parisites into the environment.