C. cassis var. spinifera a after Playfair; b, c after Deflandre, 1929 (notice the changes between a and b)
Centropyxis cassis var. spinifera Decloitre, 1954
Basionym: Difflugia constricta var. spinifera Playfair, 1918
Diagnosis: Deflandre: “Playfair gave the name var. spinifera with the spiny forms of Difflugia constricta. Its shape and accompanying dimensions allow us to place under C. cassis, this variety provided with hollow, fairly slender horns.”
Dimensions: According to Playfair: 87-72 µm
Ecology: known only from a small alpine pond, on very wet mosses.
Geographical distribution: Australia, Great Britain, France, Haute-Savoie.