Cibicides

Cibicides is a cosmopolitan genus of benthic foraminifera known from at least as far back as the Paleocene (Loeblich & Tappan, 1988) that extends down to the present.

The test, or shell, of Cibicides, which is commonly found attached, is mutlichambered, plano-convex, trochospiral, with a flat or dished-out evolute spiral side and a strongly arched, involute umbilical side. The test wall is calcareous, perforate, bilamellar, with a radial microstructure. The flat or nearly flat spiral side is coarsely perforate while the arched umbilical side is finely perforate. The apertural face and peripheral keel, where the two faces meet, are imperforate. Sutures on the spiral side are thickened and may be elevated, but are narrow and depressed on the ubilical side. The aperture a low interio-marginal equatorial opening that extends a short distance onto the umbilical side but continues along the spiral suture on the spiral side.