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
These examples selected from a great abundance of analogous phenomena
suffice to establish the individuality of the Italian stock as
distinguished from the other members of the Indo-Germanic family,
and at the same time show it to be linguistically the nearest
relative, as it is geographically the next neighbour, of the Greek.
The Greek and the Italian are brothers; the Celt, the German, and
the Slavonian are their cousins. The essential unity of all the
Italian as of all the Greek dialects and stocks must have dawned
early and clearly on the consciousness of the two great nations
themselves; for we find in the Roman language a very ancient word
of enigmatical origin, -Graius-or -Graicus-, which is applied to
every Greek, and in like manner amongst the Greeks the analogous
appellation --Opikos-- which is applied to all the Latin and
Samnite stocks known to the Greeks in earlier times, but never to
the Iapygians or Etruscans.
