Deharvengia japonica  Bobrov, Shimano & Mazei, 2012

Diagnosis. The shell is large, colorless, transparent, and ovoid to broadly ovoid, tapering towards the front end. It is dorsoventrally flattened and narrowly elliptic in cross-section. The aperture is narrowly elliptic, located on the ventral side at approximately 6/7 of the total shell length, and surrounded by a thin organic lip. A small cap is present on the dorsal side of the shell, bordered by a narrow organic lip. The shell is covered with elliptical, flat silica plates (idiosomes), measuring approximately 7 × 11 µm. These plates are arranged regularly in up to 18 transverse and 13—15 longitudinal rows. On the dorsal side of the cap, the rows follow the outline of the shell. Flat, transparent clavate spines, about 10 µm in length, are located on each side of the shell, between the posterior end and the middle of the test.

The shell is notably large, measuring slightly less than 100 µm in length, which is almost twice the average size of soil testate amoebae. The population is monomorphic, with low variation coefficients for all morphological characteristics, ranging from 3.0% to 9.1% across the six variables under investigation.

Dimensions: Bobrov, Shimano & Mazei (2012): Shell length 86—97 µm; width 69—79 µm; breadth 32—39 µm.

Habitat: This species inhabits soil, particularly the organic surface layer among mountain pine (Pinus pumila) vegetation, which consists mainly of fallen needles (coniferous semi-decomposed litter – organic surface soils). It is found in mountain gravelly soils that are seasonally freezing, with a high moisture content, formed on volcanic rocks. Additionally, this species was observed in another microhabitat at the same location, among tall grasses.

Geographical distribution: Mikuriga-pond, Murodo, Japan.