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
Labienus moved from Agedincum up the left bank of the Seine with
a view to possess himself of Lutetia (Paris), the town of the Parisii
situated on an island in the Seine, and from this well-secured
position in the heart of the insurgent country to reduce it again
to subjection. But behind Melodunum (Melun), he found his route
barred by the whole army of the insurgents, which had here taken
up a position between unassailable morasses under the leadership
of the aged Camulogenus.
Labienus retreated a certain distance,
crossed the Seine at Melodunum, and moved up its right bank
unhindered towards Lutetia; Camulogenus caused this town to be
burnt and the bridges leading to the left bank to be broken down,
and took up a position over against Labienus, in which the latter
could neither bring him to battle nor effect a passage
under the eyes of the hostile army.