I also agree with gflat... the one seems Astreopora, the second... maybe a echino, but itÃ"šÃ‚´s impossible to be sure without seeing the skeleton. And the third... definitely not a galaxea for me, it seems to be an SPS, it could even be porites (the pics isnÃ"šÃ‚´t clear), but with that polyps... probably an encrusting monti.