HILTERMANNIA N. GEN. (FORAMINIFERIDA) DEL CRETACICO SUPERIOR (MAASTRICHTIANO) DE ARGENTINA

Abstract

A new genus, Hiltermannia, is erected under the Bolivinitidae Cushman; it includes the new species Hiltermannia kochi. The new genus is characterized by possessing an elongate, biserial test, the last chambers of adult specimens tending to become uniserial; the plane of biseriality is strongly twisted; randorn coiling; the chambers are subreniform, broad, low, subglcbular, slightly overlapping the earlier ones and added more or less 160º apart, and those of succesive whorls at 220º more or less in the coiling direction; periphery rounded, sutures depressed, with lobulations at the lower margin in the last chambers; wall calcareous, perfcrate, radial in structure; the aperture is an elongate loop extending from the base of the chamber in early stages, becoming areal in later stages, although never central and completely terminal, and retaining the apertural suture line down to the chamber base, with bordering lip and internal simple tooth plate.