These are two marine crab species (which ones?
and the one on the left appears to have eggs coating her upper carapace)
as portrayed in tiles on the walls of the downtown-bound landing of the NYC subway stop (A-B-C)
at 81st and Central Park West. (ISO, no zoom, no flash).
They look like they might be anomuran crabs, possibly porcillanids. They're awesome whatever they are!