psephisma

Callixenus, a senator, proposed that the people should at once proceed to pass its verdict on the generals, though they had been only partially heard in their defence; and, moreover, that they should all be included in one sentence, though it was contrary to a rule of Attic law, known as the psephisma of Canonus, to indict citizens otherwise than individually.

A Smaller history of Greece From the earliest times to the Roman conquest William Smith 1853