Centropyxis pontigulasiformis Beyens, Chardez & De Bock, 1986
Diagnosis: shell formed of two distinct parts: the shell body, and a rather large semi-circular visor. The body is perfectly spherical and is perforated by a small circular aperture. The shell wall is composed of an organic matrix, incorporating fine plate-like polymorphous mineral particles. The visor which expands fan-like above and around the aperture, is mostly embossed with more voluminous quartz particles, in particular at the rim. Seen from an apertural view, this visor is as large as the shell body.
Dimensions: Beyens et al: diameter of the shell 58-62 µm, length of the visor 24-28 µm (n=5); diam. of aperture 8-10 µm; total length 82-90 µm
Ecology: mosses and Sphagnum. Canadian arctic, the Netherlands ('t Hol, Laegieskamp), Germany (Rotes Wasser) and Austria (Tirol).