what is this?

Hi this was on one of my LR's when I bought it can someone take a guess at what it is? it is about the size of a small pee. The pic is not that good but it is throught a magnifying glass. the brown areas are purple and some floresent green under the attinic. It has little cup like feet sort of greeny yellow in color. also I have some very small hard, white, egg like things on some of my rock and glass I think maybe snale. when they hatch they resemble a clam but nothing left in side.
removed pics.

thank you,
Bill