I have the coral, looking like yours, only the sheaths of polyps is pronunciated, was never be able to confirm is it white lemnalia, as LFS marked, or not:

Not much of info on the web too. Mine tolerates the very low light, polluted water, only becomes darker, pinkish - as a white xenia in the same conditions. The only requirement is to be in a high flow.
And the purple lemnalia has similar polyps (without sheaths) and sclerites:

This was high light and high flow, never grow, had the steam rot.
Looking for any additional info, including ID confirmation, and any care tips, including the similar looking species.
What conditions yours likes?