The morphology of the gametes of four species of nummulitids is compar
ed. Heterostegina depressa, Cycloclypeus carpenteri and Operculina cf,
complanata have biflagellated gametes as most foraminifera. Nummulite
s venosus has triflagellated gametes which previously has been documen
ted only in gamontogamous species. In addition, gamete flagella of Ope
rculina cf. complanata have mastigonemes, a feature previously reporte
d in only two foraminifera: the ''lower'' allogromiid Boderia turneri
and the ''higher'' amphisteginid Amphistegina gibbosa.