Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Councils of Ancyra, Gangra, Neocæsarea, Antioch and Laodicea, which Canons were Accepted and Received by the Ecumenical Synods.: Canon XIV

Canon XIV.

The chorepiscopi, however, are indeed after the pattern of the Seventy; and as fellow-servants, on account of their devotion to the poor, they have the honour of making the oblation.

Notes.

Ancient Epitome of Canon XIV.

[Vide ante, as in many mss. the two canons are united in the Ancient Epitome.]

Van Espen.

The reference to the Seventy seems to intimate that the Synod did not hold the chorepiscopi to be true bishops, as such were always reputed and called successors, not of the Seventy disciples but successors of the Twelve Apostles.  It is also clear that their chief ministry was thought to be the care of the poor.

Zonaras and Balsamon would seem to agree in this with Van Espen.  See on the whole subject the Excursus on the Chorepiscopi.