Selection of formainiferan shells (tests). Science Image

Ref: 500093



Foraminiferan shells. Light micrograph using transmitted light, of assorted species of shells belonging to the order Foraminifera. Single-celled protozoans inhabit these shells which are composed of several chambers and usually penetrated by pores through which the cellular contents is extruded. The organisms live in the sea or salt-water lakes. Foraminiferan shells form an important component of chalk and of many deep sea oozes. In previous geological ages Foraminifera occurred in such enormous numbers that their shells, largely of calcium carbonate, have formed immense fossil deposits seen today as limestone. Magnification: to be advised