ostracods - tiny crustaceans aka 'seed shrimp'

and various other tiny, tiny water beasties including some sort of fly larvae (just to right of center, upper right quadrant) and some other teensy shrimp like things - I think they are copepods (dead center). This incredible tableaux was all in a tiny puddle that I think may have been fed by a tiny spring (the hole), formed on a walkway in a park. the very clear water couldn't have been more than a cm deep.