Diagnosis: Test elongated to broadly pyriform or lens- or spindle-shaped, with a layer of small siliceous xenosomes and usually with some organic particles of debris. Test colorless or yellowish to almost black; aperture straight or oblique; test up to 1000 µm long. Usually with 1-8 nuclei, sometimes up to 30. Nuclei spherical, ovular.
Typespecies: Lacogromia cassipara
Lacogromia squamosa (Penard, 1899)
Lacogromia brunneri (Blanc, 1886)
Lacogromia palustris (Thomas, 1961)