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
Not only, however, did a dangerously long interval elapse, in the
event of mercenaries being required, ere they could be got ready,
while the Roman militia was able at any moment to take the field, but
--which was the main matter--there was nothing to keep together the
armies of Carthage but military honour and personal advantage, while
the Romans were united by all the ties that bound them to their common
fatherland.
The Carthaginian officer of the ordinary type estimated
his mercenaries, and even the Libyan farmers, very much as men
in modern warfare estimate cannon-balls; hence such disgraceful
proceedings as the betrayal of the Libyan troops by their general
Himilco in 358, which was followed by a dangerous insurrection of the
Libyans, and hence that proverbial cry of "Punic faith," which did the
Carthaginians no small injury. Carthage experienced in full measure
all the evils which armies of fellahs and mercenaries could bring upon
a state, and more than once she found her paid serfs more dangerous
than her foes.