the first is a just a mushroom. it isn't a ricordia
the second is either 1 of 2 things .. its either a sponge as stated or a dead coral skeleton. I definitly don't see anything as far as living polyps goes on it.
Very nice fungia. Ditto on what everyone else said. Comment about the fungia though is that you should try and keep the sand from getting onto the fungia. They will expend a lot of energy constantly trying to slough off the sand and it might suffer in the long run.