Pusillolucina biritika sp. nov. A, B South Madagascar east of Cap Antsirabe, 49–52 m, ATIMO-VATAE stn TP11, 25°02.8'S, 47°01.3'E. (MNHN) C–E, L, M South Madagascar off Baie Fort-Dauphin 54–56 m, ATIMO-VATAE stn TP18, 25°02.45'S, 47°03.26'E (MNHN) F–K Northwest Madagascar, S of Cap St Sébastien, 42–44 m, MIRIKY stn DW3202, 12°35.6'S, 48°49.9'E (MNHN). A Holotype, stn TP11 (MNHN-IM-2000-35109), L 1.1 mm B paratype stn TP11 (MNHN-IM-2000-35181) L 1.5 mm C paratype stn TP18 (MNHN-IM-2000-35110) exterior of left valve, L 1.3 mm D paratype stn TP18 (MNHN-IM-2000-35110) interior of right valve, L 1.3 mm E paratype stn TP18 (MNHN-IM-2000-35110) exterior of left valve L 1.5 mm F paratype stn DW3202 (MNHN-IM-2000-35111). exterior of right valve L 1.4 mm G paratype stn DW3202 (MNHN-IM-2000-35111). exterior of right valve L 1.1 mm H paratype stn DW3202 (MNHN-IM-2000-35111) interior of left valve L1.4 mm I paratype stn DW3202 (MNHN-IM-2000-35111) interior of right valve L 1.3 mm J, K detail of hinge teeth of H and I. L, M Paratype TP18 (MNHN-IM-2000-35110) exterior of left valve and interior of right valve L 1.2 mm.