Observational data around large miliolid foraminifera from the polar oceans

The genus 'Cornuspiroides» Cushman is discussed in detail and a new species 'C. rotundus,» comprising an antarctic evolutionary line, is differentiated by morphometric analysis from the Arctic 'C. striolatus» (Brady). The potential evolutionary lines and the ecology of the two closely related species are discussed in relation to substrate and water mass characteristics as well as standing stocks and diversities of associated life and dead benthic foraminiferal faunas.