When I pulled the "algea caps" off they kinda resembled flowers, they had 'petal' like feathery arms that cover just the top of the closed zoa, and they have a 'stem' like part that extends slightly down inside.
In the first pic listed above, I hadn't done anything to them yet, and almost all of them had these brownish green algea caps on them. Before the second pic, I put them in an area of high flow and removed a few of the algea caps, in the third I think I took a few more off.