Test biconvex, lenticular with prominent radial spines.
Genera of family “Calcarinidae”
Test globular but the three or four large thick and protruding spines may give a triangular to tetrahedal appearance.
Lenticular biconvex test, commonly with a few to many heavy and blunt to splayed or bifurcating radial spines.
Single or compound umbilical plug, aperture restricted by a toothplate that protrudes with a free edge into the aperture and forms an umbilical spiral canal.
Large globular test with slightly projecting spines or tubercles.