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 XCVIII

Canon XCVIII.  (Greek cii.)

Of the peoples which never had bishops.

It seemed good that such peoples as had never had bishops of their own should in no way receive such unless it had been decreed in a plenary council of each province and by the primates, and with the consent of the bishop of that diocese to which the church belonged.

Notes.

Ancient Epitome of Canon XCVIII.

Whoso never heretofore had a bishop of their own, unless the general synod of the Province shall agree to it, and the Primate, in agreement with him to whom the province in which the Church is, is subject, shall not have bishops of their own.

This canon is Canon iv. of the Synod of Carthage, a.d. 407.