Corythion nebeloides  Bonnet, 1960

Diagnosis: Shell plagiostome, rarely acrostome, large in size, hyaline, noticeably elliptical in lateral view, with more pronounced flattening on the ventral side. Aperture without invagination, with a subcircular outline, bordered by a hyaline chitinous thickening with a finely scalloped appearance. Shell covering composed of elliptical siliceous scales, approximately 2.5 × 1.8 µm in size, with a lenticular cross-section, relatively uniform in size, and sometimes partially overlapping.

Dimensions: Bonnet and Thomas (1960): Shell length: 23—27 µm, width 12—15 µm.

Ecology: Bonnet (1960): “Although no statistical conclusions can be drawn due to the lack of data, it is notable that this species is present in two soils with a pH of 5, but absent in other soils with a pH of 7. This observation appears to align with the acidophilic nature of Corythion.”

Remarks: Bonnet (1960): “This species is characterized by its large size, its pseudostome without invagination, and the absence of a constriction in the pseudostomial region. These two features distinguish it from Corythion dubium var. gigas Thomas. Its specific name originates from the fact that, at first glance, some acrostome individuals could be mistaken for Nebela.”