The stratigraphic usefulness of calcareous nannofossils proved itself again during Leg 178. This group provides reliable age constraints for the Pleistocene at Sites 1096 and 1101, correlating well with the paleomagnetic record from each site. Considering that the reference ages for the biostratigraphic events were drawn from studies well to the north of the locale of this leg, this is quite an interesting phenomenon. Although species diversity and total abundance were often low, the reliability of the biostratigraphic ages produced was not grossly affected. The many previous studies that included similar observations of nannofossils (general abundance and specific species) in the Southern Ocean from the Pleistocene allow us to conclude that they had a circumpolar distribution for at least several periods of time in this interval. The periodic nature of the occurrences of nannofossils in the sediment, and their often low abundance, seems to indicate that conditions were perhaps not optimal but were consistently present to allow production and subsequent preservation in the sediment. The fact that calcareous nannofossils occur in an interval that contains rare, fragmented, and reworked biosiliceous species begs further study from numerous sites around the Antarctic continent.