Centropyxis notonyx  Jung, 1942

Diagnosis: Shell brown, chitinous, almost free of xenosomes, wide, with hooked spines. Larger mineral particles attached to the fundus. Pseudostome always elliptical, anterior border of the lip not very clearly defined, lip generally narrow or rudimentary. Spines at different heights on the shell and a sharply indented saddle dent at the front.

Dimensions: Length 63-73 µm (without spines); width 53-58 µm (without spines); height 47-65 µm (without spines); pseudostome 17×30 to 27 µm; spines 13-24 µm.

Ecology: Freshwater. On submerged plant parts at the edge of the open water. C. notonyx was found in the pond on Isla Calbuco, Chile.