Irenaeus is posting his admirable 'Revisionist Dictionary' over at StandFirm. He has some wonderful definitions listed, but he omitted one. So here's my definition of 'Presiding Bishop'.
PRESIDING BISHOP: The Presiding Bishop of The Episcopal Church (TEC) is the Heresiarch of the denomination. While she is not a primate, she functions as one in her dealings with foreign primates. It is believed that she is a marsupial.