Difflugia brevicolla Cash & Hopkinson, 1909
Diagnosis: Shell transparent, yellow or light brown, spherical with a short collar; this collar, in ventral view, varies from being easily visible to being obscured by shell components, but at either extreme it is usually apparent in apertural view; shell composed mainly of a mixture of small diatom frustules, small pieces of quartz and siliceous cysts of chrysomonad flagellates; aperture circular with a regular even outline.
Dimensions: Length 66-110 µm; breadth 48-97 µm; diameter of aperture 22-42 µm; my measurements: 70-115 µm.
Ecology: Freshwater sediments, Sphagnum.
Remarks: The organic cement is only occasionally visible because the shell material is so well packed, but it appears either as a matrix with small rings or as small spheres and rings. A smooth cyst membrane seals the mouth of the aperture in some specimens.