Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Synods of Sardica, Carthage, Constantinople, and Carthage Under St. Cyprian, Which Canons Were Received by the Council in Trullo and Ratified by II. Nice.: Canon CXXV

Canon CXXV.  (Greek cxxvi.)

That presbyters and clerics are not to appeal except to African Synods.

Item, it seemed good that presbyters, deacons, or other of the lower clergy who are to be tried, if they question the decision of their bishops, the neighbouring bishops having been invited by them with the consent of their bishops, shall hear them and determine whatever separates them.  But should they think an appeal should be carried from them, let them not carry the appeal except to African councils or to the primates of their provinces.  But whoso shall think of carrying an appeal across seas he shall be admitted to communion by no one in Africa.

Notes.

Ancient Epitome of Canon CXXV.

A presbyter and deacons, who has been condemned by his own bishop, let him appeal to the neighbouring bishops:  but let them not cross the sea.  In Africa they shall be excommunicated.

This is Canon xvij. of Carthage, a.d. 418.

Johnson.

A repetition of Canon 28 (31).