To me it looks like whats left of a stoneware jug that was getting washed in running water with silt sand and gravel in natural erosion over the last 100 plus years. It looks like maybe the mouth and what's left of the handle of that jug... If not that, you found a piece of piston rod from Fred Flintstone's blown engine of his car. Running late he was to get to the rock quarry on time for work.