Acmaea marcusi Righi, 1966, [Basis of the current name] Range: 20.5°S to 20.5°S; 29.3°W to 28.85°W Depth: 0 m (live 0 m) Maximum Reported Size: 18 mm Distribution: Brazil: Trindade Island, Martin Vaz Islands References: Vermeij & Snyder (1998) NSEW Combining Genera: Collisella