Difflugia carinata Van Oye, 1956
Diagnosis: Test in cross-section slightly compressed; however, the presence of a carina built up by a single row of sand-grains gives to the whole an aspect as if it were much more compressed than it actually is; indeed, without carina, the body is but very slightly compressed. On the fundus of the test, the carina may be built out of two rows of sand-grains, while there is but a single row on the lateral sides. The sand-grains on the body-surface are as numerous as in most Difflugia-species. The mouth-margin is built up by an irregular series of sand-grains. The keel makes a circle around the test and continues till ¼ of the length of the test, beginning from the aperture.
Dimensions: 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.