A. antarctica, from Grospietsch, 1971
Argynnia antarctica (Grospietsch, 1971) comb. nov.
Basionym: Nebela antarctica Grospietsch, 1971
Diagnosis: Shell strongly flattened, ratio thickness/width is about 0.5—0.6. The outline of the shell pyriform, the pseudostome edge covered with thick siliceous scales.
Dimensions: According to Grospietsch (1971): Shell length 75—85 µm; width 50—60 µm.
Ecology: Sphagnum.
Geographical distribution: Only known from Marion Island (Grospietsch, 1971).