Abstract As of mid-1978, some 480 papers have appeared on the biostratigraphy of DSDP cores, and the collections of the Project now constitute the basis for a major part of the totality of biostratigraphic studies of pelagic sequences. At least 1,249 new microfossil taxa have been described from DSDP cores. Studies based on the cores from several cruise-legs (as contrasted with single legs) have not increased as rapidly as expected. This remains a field for future exploitation, during which there will be an opportunity to develop further the quantitative aspects, which are inadequate in the biostratigraphic investigations hitherto published.