Black dogfish to the clade formed by the granular dogfish ("C. granulatum") and combtooth dogfish ("C. nigrum"). The black dogfish is a common species, with a wide but discontinuous distribution in the temperate waters of the Atlantic Ocean; its range abuts, but does not extend into, the Arctic Ocean. In the northeast, it occurs from Iceland to Sierra Leone, including the Faroe Islands, southern Norway, and the Rockall Trough and Porcupine Seabight off Ireland. In the northwest, it is found from southern Greenland and Baffin Island to Virginia, being particularly abundant in the Laurentian Channel, and may occur further south to the
Rockall 17.15 m (56.27 ft). It is often washed over by large storm waves, particularly in winter. There is a small ledge of , known as Hall's Ledge, from the summit on the rock's western face. It is the only named geographical location on the rock. The nearest point on land from Rockall is 301.3 km, or 162.7 nmi, east at the uninhabited Scottish island of Soay in the St Kilda archipelago. The nearest inhabited area lies 303.2 km, or 163.7 nmi, east at Hirta, the largest island in the St. Kilda group, which is populated intermittently at a single military