Several arguments can be made that abba Amphilocius from Paris was indeed a presbyter:
a) One of the canons of this council addresses abbots from both the monasteries and parishes. Afterwards it refers collectively to abbates vel presbyteri (c. 11, [1348]);
b) The signature of Abbot Amphilocius is positioned immediately after those of the bishops and before those by the presbyters. It seems, therefore, that his rank was at least equal to that of the presbyters.
Hence, there are three possibilities:
a) Amphilocius was an abbot at a monastery, but he also held the rank of a presbyter;
b) abba is used here as a honorific title - Amphilocius was reverenced in such a way, that fellow Christians called him abba - "father";
c) Amphilocius was an important presbyter - he was, for example, in charge of an important basilica, martyrium, etc.
For further discussion on abbots-presbyters, see discussion in [810].
Presbyter Baudardes from Avranches also signed (as Baudastes) the acts of the third council of Orléans (AD 538) [1331].