Genus Heleoporella Coûteaux, 1978

Diagnosis: Test not compressed; pseudostome circular and provided with a rim; covering composed of irregular plates and round to oval scales arranged without order.

Monospecific.
Type species: Heleoporella caustica Coûteaux, 1978.

Heleoporella caustica Coûteaux, 1978

Diagnosis: Acrostomic test, very small, hyaline, highly transparent, ovoid, not compressed. Covering composed of a mixture of thin, irregular plates and round scales of the same type as those of Trinema lineare. Pseudostome more or less circular, bordered internally by a thickened rim.

Dimensions: Length: 17.4–23.2 µm; width: 11.6–17.4 µm; pseudostome diameter: 5.8–7.0 µm.

Ecology: Mixed wood, humid soil.

Distribution: Japan.

Remarks: Coûteaux, 1978: “This very small species may be confused with Schoenbornia viscicola or with Heleopora decloitrei or H. minuta. However, the presence of round scales identical to those of Trinema lineare, together with a slight rim surrounding the pseudostome, excludes the first possibility. Although closer to the genus Heleopora, it differs from it by the circular, non‑notched pseudostome and by its non‑compressed shape.”