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
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
But, in the first place, there were associated with the holding of the supreme magistracy various honorary rights, partly personal, partly hereditary; thus the honour of a triumph was regarded as legally dependent on the occupancy of the supreme magistracy, and was never given to an officer who had not administered the latter office in person; and the descendants of a curule magistrate were at liberty to set up the image of such an ancestor in the family hall and to exhibit it in public on fitting occasions, while this was not allowed in the case of other ancestors.(4)
4. Whether this distinction between these "curule houses" and the other families embraced within the patriciate was ever of serious political importance, cannot with certainty be either affirmed or denied; and as little do we know whether at this epoch there really was any considerable number of patrician families that were not yet curule.
It is as easy to be explained as it is difficult to be vindicated, that the governing aristocratic order should have allowed the government itself to be wrested from their hands far sooner than the honorary rights associated with it, especially such as were hereditary; and therefore, when it was obliged to share the former with the plebeians, it gave to the actual supreme magistrate the legal standing not of the holder of a curule chair, but of a simple staff-officer, whose distinction was one purely personal.
Of greater political importance, however, than the refusal of the -ius imaginum- and of the honour of a triumph was the circumstance, that the exclusion of the plebeians sitting in the senate from debate necessarily ceased in respect to those of their number who, as designated or former consuls, ranked among the senators whose opinion had to be asked before the rest; so far it was certainly of great importance for the nobility to admit the plebeian only to a consular office, and not to the consulate itself.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/2-03-equalization-orders-aristocracy.asp?pg=5