A patera is a round, shallow bowl used during religious rituals to pour out libations of wine or oil (usually over an altar). Some have a raised center so it can be held in the palm of the hand, the thumb is then placed on the raised center so that it does not profane the libation as it is poured out. The patera is often depicted on coins being held by gods and goddesses as a symbol of their divine rank or of rites carried out in their honor.

A penates (housegod) holding a patera and cornucopia