Argynnia caudata (Leidy, 1879)
Basionym: Nebela caudata Leidy, 1879

Diagnosis: Shell ovoid with a rounded or angulous fundus ornated with 3 to 5 hollow horns (generally 4); covered with polygonal or circular scales, jointing or rarely overlapping.

Dimensions: Length 78—90 µm. My measurements 60—92 µm.

Ecology: Sphagnum-vegetation.