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
Aristotle, who died about fifty years before the commencement of the
first Punic war, describes the constitution of Carthage as having
changed from a monarchy to an aristocracy, or to a democracy inclining
towards oligarchy, for he designates it by both names. The conduct
of affairs was immediately vested in the hands of the Council of
Ancients, which, like the Spartan gerusia, consisted of the two kings
nominated annually by the citizens, and of twenty-eight gerusiasts,
who were also, as it appears, chosen annually by the citizens.
It was
this council which mainly transacted the business of the state-making,
for instance, the preliminary arrangements for war, appointing levies
and enlistments, nominating the general, and associating with him a
number of gerusiasts from whom the sub-commanders were regularly
taken; and to it despatches were addressed. It is doubtful whether by
the side of this small council there existed a larger one; at any rate
it was not of much importance.