summoner

noun

1. One who summons or evokes, particularly in legal contexts.
2. (historical)An apparitor; an officer of an ecclesiastical court whose job it was to deliver a summons to an offending member of the diocese.
3. 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.”