The extinct Pleistocene buccinid gastropod Atractodon stonei (Pilsbry 1893), formerly known as Neptunea stonei (Pilsbry), has been found in a southern Nova Scotian deposit. The species had been previously reported only from (presumably) Sangamon deposits at Nantucket Island, Massachusetts and at other locations south to Cape Hatteras, North Carolina. Associated molluscs from all A. stonei deposits show that it probably lived in about 5 to 20 fm and in a climate like that of the present Acadian marine zoogeographic region.Although the Nova Scotian specimens produced radiocarbon ages of 38 000 years B.P. stratigraphic and paleoclimatological data indicate Sangamon age and the radiocarbon dates are presumed to be too young. Atractodon stonei may qualify as a useful Pleistocene (Sangamon) index fossil representative of relatively specific paleoecological conditions.