Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Second Ecumenical Council:  The First Council of Constantinople.: Canon I

p. 172 Canons of the One Hundred and Fifty Fathers who assembled at Constantinople during the Consulate of those Illustrious Men, Flavius Eucherius and Flavius Evagrius on the VII of the Ides of July. 228

The Bishops out of different provinces assembled by the grace of God in Constantinople, on the summons of the most religious Emperor Theodosius, have decreed as follows:

Canon I.

The Faith of the Three Hundred and Eighteen Fathers assembled at Nice in Bithynia shall not be set aside, but shall remain firm.  And every heresy shall be anathematized, particularly that of the Eunomians or [Anomæans, the Arians or] Eudoxians, and that of the Semi-Arians or Pneumatomachi, and that of the Sabellians, and that of the Marcellians, and that of the Photinians, and that of the Apollinarians.

Notes.

Ancient Epitome of Canon I.

Let the Nicene faith stand firm.  Anathema to heresy.

There is a difference of reading in the list of the heretics.  The reading I have followed in the text is that given in Beveridge’s Synodicon.  The Greek text, however, in Labbe, and with it agree the version of Hervetus and the text of Hefele, reads:  “the Eunomians or Anomæans, the Arians or Eudoxians, the Semi-Arians or Pneumatomachi, the Sabellians, Marcellians, Photinians and Apollinarians.”  From this Dionysius only varies by substituting “Macedonians” for “Semi-Arians.”  It would seem that this was the correct reading.  I, however, have followed the other as being the more usual.

Hefele.

By the Eudoxians, whom this canon identifies with the Arians [according to his text, vide supra,] is meant that faction who, in contradistinction to the strict Arians or Anomæans on one side, and the Semi-Arians on the other side, followed the leadership of the Court Bishop Eudoxius (Bishop of Constantinople under the Emperor Valens), and without being entirely Anomæan, yet very decidedly inclined to the left of the Arian party—probably claiming to represent the old and original Arianism.  But this canon makes the Semi-Arians identical with the Pneumatomachians, and so far rightly, that the latter sprang from the Semi-Arian party, and applied the Arian principle to their doctrine of the Holy Ghost.  Lastly, by the Marcellians are meant those pupils of Marcellus of Ancyra who remained in the errors formerly propounded by him, while afterwards others, and indeed he himself, once more acknowledged the truth.

Footnotes

Such is the caption in the old Greek codices.  The vijth of the Ides is July 9th.  “From this (says Hefele) we may conclude that this synod which according to Socrates, H. E., v. 8) begun May 381, lasted until July of that year.”