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
So they left the constitution untouched, and the chiefs of the
government in full enjoyment of their exclusive privileges and of the
public property. It was merely proposed and carried, that of the two
commanders-in-chief, who at the end of the Libyan war were at the head
of the Carthaginian troops, Hanno and Hamilcar, the former should be
recalled, and the latter should be nominated commander-in-chief for
all Africa during an indefinite period. It was arranged that he
should hold a position independent of the governing corporations
--his antagonists called it an unconstitutional monarchical power,
Cato calls it a dictatorship--and that he could only be recalled and
placed upon his trial by the popular assembly.(2)
2. The Barca family conclude the most important state treaties, and
the ratification of the governing board is a formality (Pol. iii. 21).
Rome enters her protest before them and before the senate (Pol. iii.
15). The position of the Barca family towards Carthage in many points
resembles that of the Princes of Orange towards the States-General.