Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
They had become sufficiently convinced of the
incorrigibleness of the party in power: the fact that the governing
lords had even in the last war neither forgotten their spite nor
learned greater wisdom, was shown by the effrontery bordering on
simplicity with which they now instituted proceedings against Hamilcar
as the originator of the mercenary war, because he had without full
powers from the government made promises of money to his Sicilian
soldiers.
Had the club of officers and popular leaders desired to
overthrow this rotten and wretched government, it would hardly have
encountered much difficulty in Carthage itself; but it would have met
with more formidable obstacles in Rome, with which the chiefs of the
government in Carthage already maintained relations that bordered on
treason.
To all the other difficulties of the position there fell
to be added the circumstance, that the means of saving their country
had to be created without allowing either the Romans, or their own
government with its Roman leanings, to become rightly aware of
what was doing.