Diagnosis: Shell pyriform, compressed, with a more or less pronounced aboral protuberance; shell composed of small to large pieces of quartz; pseudostome surrounded by smaller particles. With zoochlorellae. Nucleus large, with more or less spherical nucleoli, most of them layered in the periphery, but also in the center.
Dimensions: My measurements: length 380-434 µm; nucleus about 50 µm in diameter.
Ecology: In sediments of ditches.
Remarks: Shells of this species or variety are rare. I found this species only in the sediment of a ditch in the nature reserve Naardermeer in the Netherlands. I am not convinced that this is a separate species. I always found it together with specimens of Difflugia nodosa. Probably both species are identical. Further records are necessary. This species or variety differs from D. claviformis by its compressed shell.