Tommy Pritchard was going to school one day, and on his way he thought he heard somebody singing on the other side of a stone wall by the road, so he climbed up and looked over, and there underneath a stone he saw a sixpence, so he took it.
Every morning after that, when he went to school, he used to look in the same place, and he always found a sixpence.
His father noticed he was always spending money in the sweet-shop, so he began to think Tommy was stealing from somebody, and one day he asked him where he got the money. Tommy wouldn’t tell at first, but his father threatened to beat him, so he told him where he got his sixpences.
Next morning he went to look in the same place for his sixpence, and he found nothing but a cockle-shell. And he never saw anything but a cockle-shell there afterwards.
Tommy Pritchard – Welsh Fairy-Tales And Other Stories