On the first day of the Conference, the Donatists challenged the list of the signatures of the Catholic bishops on the document in which they had assigned their representatives. The roll call followed, in which the tribune Marcellinus, who presided, called the Catholic bishops one by one, and their Donatist counterparts were to identify them. Then the roll call proceeded in the opposite way, with the Donatist bishops identified by the Catholics.

The presence of Cattus may have been considered unnecessary if there really were no other Donatists in that place.