Difflugia carinata  Van Oye, 1956

Diagnosis. Shell slightly compressed in cross-section; but the presence of a carina formed by a single row of sand grains creates the impression of greater compression than is actually the case. Without the carina, the body is only minimally compressed. At the fundus of the test, the carina may consist of two rows of sand grains, while the lateral sides feature only a single row. The body surface is densely covered with sand grains, similar to most Difflugia species. The margin of the aperture is irregular, composed of a series of sand grains. The keel forms a continuous circle around the shell and extends up to one-quarter of the shell’s length from the aperture.

Dimensions. Van Oye (1956): Shell length 92 µm; width 52 µm; aperture 18 µm.

Ecology. Freshwater. Sphagnum swamp, Dunedin, New Zealand.

Reference. Van Oye, P., 1956. On the Thecamoeban fauna of New Zealand with description of four new species. Hydrobiologia, VIII, 1-2.