Pseudodifflugia sylvarum Penard, 1917
Diagnosis: Shell grey or bright yellow, ovoid, strongly compressed, like an almond; Shell wall a chitinous membrane covered with small flat mineral particles, sometimes some larger particles are present, giving the shell a more rough appearance. Aperture somewhat cut off, small, oval, without any thickened rim. Nucleus vesicular, relatively large, finely granulated, usually with one eccentric and relatively very small nucleolus. Filopodia delicate, long and branching, with small veils and granules along the base of the filopodia. Cytoplasm divided into two zones: one large zone above the pseudostome with food particles, numerous small bi-refringent elliptical grains and one zone with the nucleus and without granules.Living cells collect a bunch of debris around their pseudostome.
Dimensions: Penard: shell length c. 45-50 µm, nucleus 12-14 µm .
Ecology: Penard reported his specimens from mosses on trees and walls.