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
Nothing is more certain than that this earliest constitutional scheme did not originate in Rome; it was a primitive institution common to all the Latins, and perhaps reached back to a period anterior to the separation of the stocks. The Roman constitutional tradition quite deserving of credit in such matters, while it accounts historically for the other divisions of the burgesses, makes the division into curies alone originate with the origin of the city; and in entire harmony with that view not only does the curial constitution present itself in Rome, but in the recently discovered scheme of the organization of the Latin communities it appears as an essential part of the Latin municipal system.
The essence of this scheme was, and remained, the distribution into curies. The tribes ("parts") cannot have been an element of essential importance for the simple reason that their occurrence at all was, not less than their number, the result of accident; where there were tribes, they certainly had no other significance than that of preserving the remembrance of an epoch when such "parts" had themselves been wholes.(7)
7. This is implied in their very name. The "part" (-tribus-) is, as jurists know, simply that which has once been or may hereafter come to be a whole, and so has no real standing of its own in the present.
Do you see any typos or other mistakes? Please let us know and correct them
Reference address : https://www.ellopos.net/elpenor/rome/1-05-original-constitution-rome.asp?pg=15