Centropyxis gasparella Chardez, Beyens et De Bock, 1988
Diagnosis: Shell globular or very slightly oval in apertural view; regularly inflated in lateral view, slightly compressed at the dorsal anterior part. The shell has a greenish tint, and is composed of small polymorphous mineral particles, cemented onto an organic matrix. The aboral region of the shell mostly bears a few mineral particles of larger size. The structure of the aperture is the most striking feature of this species. The walls of the aperture form a trapezium, from which originate two broad internal extensions, which are perforated by two oval openings. These extensions reach the dorsal inner part of the shell, in which they are incorporated. Situated in front of this aperture, an ± oval depression can be observed. Together with the aperture it forms the characteristic key-hole structure.
Dimensions: Length of test: 100-110 µm, width: 95-105 µm, height: 40-44 µm, diameter of the aperture: 26-30 µm.
Ecology: submerged mosses, sediment, Canadian Arctic, Devon Island NWT.