Trinema lenticularis  Siemensma et Łuców, 2025

Diagnosis: In ventral view, shell elongated-ovoid, in cross-section slightly compressed, a little deeper than wide. In lateral view, shell bi-convex with rounded corners, at the ventral-anterior side interrupted by an aperture. Shell composed of two types of scales: (1) large round scales that more or less overlap each other and (2) smaller broadly elliptical to oblong scales that lie beneath the larger scales and cover the gaps and transitions between the large scales. Pseudostome circular, invaginated and bordered by one row of small denticulate apertural scales.

Dimensions: Łuców et al. (2024): Shell length 31.8—49.6 µm; width 14.1—19.6 µm; depth 15.0—20.9 µm; aperture 5.3—10.7 µm; large scales 3.3—4.6 µm.

Habitat: Freshwater, peatland.

Geographical distribution: Type locality: Khar Zurkhnii Khukh Nuur fen, Mongolia.

References: Łuców, D., Siemensma, F., Avirmed, D., Obremska, M., Słowiński, M., Zawiska, I., 2025. Morphological and morphometric investigations on testate amoebae from Mongolia with descriptions of a new genus and four new species. European Journal of Protistology 97, 126128. https://doi.org/10.1016/j.ejop.2024.126128