The history of investigations of planktonic foraminifera leading to their current, wide applications in biostratigraphic correlation of Mesozoic and Cenozoic marine sediments can be traced to the discovery by Owen (1867) of the floating habit of certain foraminifera, later confirmed by Brady (1884), and the recognition by Murray and Renard (1891) that their shells constitute a major portion of deep-sea sediments over large regions of the seafloor. The utilitarian value of planktonic foraminifera in paleoecological analysis is also widely accepted today. Fortunately for students of paleoecology, many species of planktonic foraminifera are still extant and live in large numbers in all oceanic regions. Their areal, vertical and seasonal occurrences have been resolved to such a degree that a global synthesis of their distribution patterns is now available (e.g. Bradshaw, 1959; Belyaeva, 1964; Be and Tolderlund, 1971).