Description of Amphisteginidae
provided by BioPedia
Asterigerinid foraminifera, test lenticular, biconvex, may be bi-involute or partially evolute on spiral side, with distinctive umbilical plug; internal toothplate dividing almost completely each chamber, producing an irregular stellate pattern on the umbilical side; aperture an umbilical slit bordered by a lip; surface smooth except for the apertural region covered with fine papillae.
