Nine carnivorous gastropod borings were found in Trentonian (Middle (Ordovician) brachiopods (Dalmanella, Sowerbyella, and Hesperorthis) from limestones in New York and Michigan. These are probably the oldest carnivorous snail borings yet described. Criteria are reviewed for determining (1) whether a hole in a shell is a snail boring and (2) which of the associated gastropods was the carnivore. The caenogastropod Subulites was probably the carnivorous snail, and specimens of it were found in the same bed with a snail-bored brachiopod.