a leader of Spanish mercenaries in the service of Syracuse at the time when that city was besieged by Marcellus.
After the departure of Epicydes, and the massacre of the officers whom he had left in the command, six new praetors were appointed, of whom Mericus was one; but he entered into a correspondence with his countrymen in the Roman service; and being entrusted with the charge of part of the island of Ortygia, took the opportunity to admit a body of Roman troops into that fortress.
By this means Marcellus became master of the citadel, which soon led to the capture of the whole city, B. C. 212. Mericus was rewarded for his treachery by appearing in the ovation of the Roman general adorned with a crown of gold, besides the more substantial benefits of the Roman franchise, and an assignment of 500 jugera of land. (Liv. 25.30