Test conical, apical proloculus followed by a few incomplete annular chambers that rep-resent a reduced early spiral stage, and then by numerous low rectilinear chambers that enlarge rapidly in diameter as added, base of cone convex in the early stage, later flattened to concave; wall with thin marginal epider­mis, overlying a series of narrowly spaced, short vertical exoskeletal beams that alter­nate in position with the marginal apertural openings, a shorter secondary beam occurs in front of each aperture, and a third order of shorter beams also may be present, beams intersected by at least two orders of horizon­tal rafters that parallel the septa, the series of beams and rafters producing a complex retic­ular subepidermal network; the endoskeletal pillars are circular in section near the under-lying septum but semicircular in section toward the chamber roof; numerous apertures scattered over the base of the cone. M. Eocene; Caribbean: Leeward Islands: St. Barthelemy; Cuba; Bahamas; USA: Florida.