Difflugia difficilis
D. difficilis, (Naardermeer, Netherlands, 2019)

Difflugia difficilis Thomas, 1954

Diagnosis: Test ovoid, circular in cross-section. Aboral end of the test commonly with a not prominent, but rounded protuberance, sometimes replaced by a foreign body (diatom) which acts as the absent horn. The sides of the test converge towards the pseudostome to end in a short collar; the pseudostome is circular with a diameter varying between one-half and two-thirds of the width of the test. Test hyaline, clear, coated with siliceous particles, arranged regularly. Nucleus vesicular, spherical, with one central nucleolus and a more peripheral layer of granular material.

Dimensions: Length 83-93 µm; width 59-66 μm; pseudostome 20-27 µm; height of the collar, 6-9 μm. My measurements: L 80-117 µm; W 54-78 µm; pseudostome 26-32 µm; collar 4.7-7.4 µm high (n=6); nucleus 18.5-22.9 µm (n=2).

Ecology: Fresh water, sediment; France (1954), Belgium (Chardez, 1956), Africa (Gauthier-Lièvre et Thomas, 1958), the Netherlands (2019).

Difflugia difficilis
D. difficilis, after Thomas, 1954.
Difflugia difficilis
Difflugia difficilis
D. difficilis, nuclei
Difflugia difficilis
Difflugia difficilis
D. difficilis, nuclei
Difflugia difficilis
Difflugia difficilis
D. difficilis, with two horns (Naardermeer, Netherlands, 2019)
Difflugia difficilis
Difflugia difficilis
D. difficilis
Recent posts

Difflugia key ovoid

Difflugia Group 1 Key characters: Test < 60 µm. Test in cross section rounded. Test with rounded fundus. Pseudostome with smooth circular edge. Test not

Read More »

Difflugia: ovoid tests

Difflugia – group 1 Test < 60 µm. Test in cross section rounded. Test with rounded fundus. Pseudostome with smooth circular edge. Test not spherical

Read More »

Difflugia ampla

Difflugia ampla, after Rampi, 1950 (l) and Gauthier-Lièvre et Thomas, 1958 (r) Difflugia ampla Rampi, 1950 Diagnosis: Test broadly pyriform, with a wide and rounded

Read More »

Difflugia parva

Difflugia parva, from Gauthier-Lièvre et Thomas, 1958 Difflugia parva  (Thomas, 1954) Ogden, 1983 = Difflugia oblonga var. parva Thomas, 1954 Diagnosis: Test pyriform, tapering evenly from

Read More »