Christian Cyclopedia

(Lat. anulus piscatoris). Papal signet ring that has an image of Peter casting out or drawing in a net. with the name of the current pope above it or around the edge; used from the 13th to the 15th c. to seal private papal letters, from the 15th to the 19th c. to seal papal briefs (see Breve); hence the formula datum sub anulo piscatoris (“given under the ring of the fisherman”).