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
Family and Clan (-Gens-)
So strongly was the unity of the family realized, that even the death of the master of the house did not entirely dissolve it. The descendants, who were rendered by that occurrence independent, regarded themselves as still in many respects an unity; a principle which was made use of in arranging the succession of heirs and in many other relations, but especially in regulating the position of the widow and unmarried daughters.
As according to the older Roman view a woman was not capable of having power either over others or over herself, the power over her, or, as it was in this case more mildly expressed, the "guardianship" (-tutela-) remained with the house to which she belonged, and was now exercised in the room of the deceased house-master by the whole of the nearest male members of the family; ordinarily, therefore, by sons over their mother and by brothers over their sisters.
In this sense the family, once founded, endured unchanged till the male stock of its founder died out; only the bond of connection must of course have become practically more lax from generation to generation, until at length it became impossible to prove the original unity. On this, and on this alone, rested the distinction between family and clan, or, according to the Roman expression, between -agnati- and -gentiles-.
Both denoted the male stock; but the family embraced only those individuals who, mounting up from generation to generation, were able to set forth the successive steps of their descent from a common progenitor; the clan (-gens-) on the other hand comprehended also those who were merely able to lay claim to such descent from a common ancestor, but could no longer point out fully the intermediate links so as to establish the degree of their relationship.
This is very clearly expressed in the Roman names: when they speak of "Quintus, son of Quintus, grandson of Quintus and so on, the Quintian," the family reaches as far as the ascendants are designated individually, and where the family terminates the clan is introduced supplementary, indicating derivation from the common ancestor who has bequeathed to all his descendants the name of the "children of Quintus."
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=7