(d'Orbigny, 1839)
Spinose, symbiont-barren, with unique monolamellar wall. With large triradiate spines with hooks on edges. Unique cytoplasmic bubble capsule surrounding test. Almost exclusively carnivorous. With well timed lunar reproductive cycle, resorbing septa while undergoing gametogenesis. Characteristically with very low fossilization potential because of thin walls (Spindler et al., 1979; Hemleben et al., 1979; Hemleben et al., 1989).
Ref.: Alldredge and Jones (1973), Hemleben et al. (1979), Spindler et al. (1978, 1979).
Distribution: Tropical to subtropical, very rarely observed in sediments.