Difflugia distenda (Penard, 1899) Ogden, 1983
Original name: Difflugia acuminata var. inflata Penard, 1899
Diagnosis: Shell pyriform with the aboral extremity acutely curved towards a small central tubular horn, although the extent of the angle may be less acute in a few specimens. It has an intermediate smooth surface and thickness, being composed mainly of small to medium pieces of quartz, with occasional diatom frustules added. Aperture circular and usually surrounded by an even arrangement of small particles. Nucleus spherical, with a number of granules dispersed in the nucleus.
Dimensions: Penard (1902): 230-250 µm; Ogden: 217-270 µm long, breadth 109-135 µm. My measurements: 170-245 µm long.
Ecology: fresh water, sediments.