Argynnia columbiana (Wailes, 1925) comb. nov.
Basionym: Nebela columbiana Wailes, 1925

Diagnosis: Shell ovoid, compressed, formed of angular plates mixed with diatom frustules; fundus semicircular, furnished with a single row of 4—7 hollow spines or horns more or less irregularly arranged; shell in narrow side-view pyriform; transverse section elliptical, ratio of axis about 2 to 1; aperture elliptical with irregular margin bordered by large plates; plasma and pseudopodia normal.

Dimensions: According to Wailes (1925): Shell length without horns 174—-210 µm; breadth 140—168 µm; aperture 50—65 µm; thickness about half the breadth; length of horns 20—25 µm.

Habitat: Pools in swamp among Sphagnum and other mosses.

Geographical distribution: Cortes Island, British Columbia.