Biapertura ossiani ossiani (Sinev, 1998) comb. nov.

Sars 1901: 48–49, Pl. 9, figs 1a–d ( Alona affinis); Sinev 1998: 103–110, Fig. 1–3 ( Alona).

Diagnosis. adult male postabdomen (Fig. 16O) without marginal denticles, all denticles are substituted by groups of setulae.

Differential diagnosis. Biapertura ossiani ossiani differs from Biapertura ossiani herricki comb. nov. in the absence of 1–3 marginal denticles on postanal angle of male postabdomen.

Distribution. B. ossiani ossiani is known from the type locality only, neighborhood of Sao Paolo, Brazil.