summoner

One who summons or evokes, particularly in legal contexts.

An apparitor; an officer of an ecclesiastical court whose job it was to deliver a summons to an offending member of the diocese.

A small bell for summoning an employee to provide service.

And as they change, they set into bright relief not only outmoded honorifics and hunting horns, but silver summoners and mother-of-pearl opera glasses and all manner of carefully crafted things that have outlived their usefulness.