​GLOBIGERINA, A. d’Orbigny, a genus of Perforate Foraminifera (q.v.) of pelagic habit, and formed of a conical spiral aggregate of spheroidal chambers with a crescentic mouth. The shells accumulate at the bottom of moderately deep seas to form “Globigerina ooze” and are preserved thus in the chalk. Hastigerina only differs in the “flat” or nautiloid spiral.