An inquisitor/diplomat in the service of the Arbiter-General, responsible for ensuring that Arbitorium officials perform their duties adequately. The plural is praetori.

a new office created in 366 B.C., these people would act in place of consuls when they were away, although they primarily dealt with the administration of justice. (p. 130)

Praetor was a title granted by the government of Ancient Rome to men acting in one of two official capacities: the commander of an army, either before it was mustered or more typically in the field, or an elected magistrate assigned duties that varied depending on the historical period. The magistracy was called the praetura (praetorship). Its functions were described by the adjective: the praetoria potestas or praetorium imperium (praetorian power and authority) and the praetoria ius, a body of legal precedents set down by the praetors.