What is the white tissue?

[zdad_2004]

This white growth on the top of my coral started a couple weeks ago. The coral has been in my tank for about 6 months now and has been growing well then this started. Any ideas or recomendations?

 

[Saltyreef]

Its eating.
Those are its sweeper tenticles.
They sting for defense and pick up microorganisms for them to eat.