During Dive 12 of the 2021 North Atlantic Stepping Stones expedition, we observed this slit limpet, a kind of sea snail in the family Fissurellidae, genus Zeidora. The slit limpet was actively eating away the surface of a rock, leaving a visible, darkly colored feeding track in its wake. As this was an unusual observation, the slit limpet was collected for further analysis. Watch a video of the slit limpet.