Difflugia lebes Penard, 1899
Diagnosis: Neck sometimes indistinct, aperture large and entire. Shell very fragile, covered with siliceous flattened particles. Collar straight, rarely recurved (= var. elongata Penard). Sometimes more than 100 nuclei.
Dimensions: One of the greatest Difflugia, some reaching 400 µm in length, or more. My measurements: 235-239 µm (n=4)
Ecology: Feeds on large diatoms. Habitat ooze at the bottom of lakes, ponds.
Remarks: Though Penard mentions this a very large species, specimens in one of his stained slides (see below) are not larger than 279 µm. I’m not sure if this is a true species. What is the difference with with tests of D. urceolata with a less developed collar?
D. lebes sphaerica Gauthier-Lièvre et Thomas, 1958
Test spherical. The pseudostome is large, rounded.
Length 270-290 µm, width 270-290 µm, diameter pseudostome 130-180 µm.
D. lebes masurica Schönborn, 1965z
It differs from the typical form of small size.
Length 150–200 µm, width 150–180 µm.