Euglypha strigosa (Ehrenberg, 1848) Leidy, 1878
Diagnosis: Shell ovoid to broadly pyriform, compressed, oval in transverse section, and composed of oval overlapping shell-plates; siliceous spines may project from the junctions of the shell-plates either singly or in pairs, randomly distributed over the whole of the body surface and varying in both size and shape; spines are held in position by organic cement and are often dislodged in preparation; aperture circular and surrounded by ten to thirteen denticulate apertural-plates; each apertural-plate is roughly oval, thickened at the denticulate margin, and carries a large median tooth with either three of four smaller teeth on each side. Nucleus large with one or a few small nucleoli; cytoplasm and filopodia normal.
Dimensions: Shell length 45—100 µm; width 30—60 µm; thickness 20—30 µm; aperture diameter 12—23 µm.
Habitat: Sphagnum and other mosses, also in sediments and between water plants.
Remarks: In clonal cultures abnormal forms with a curved neck have been seen. In wild populations differences in shell size and shape were suggested by Chardez and Leclercq (1963) to be related to the type of habitat.
Several fairly stout spines, which project singly or pairwise from the junctions of the shell platelets. Plates thickened, on the anterior end usually broadly rounded, with one median tooth bent sharply towards the interior of the mouth, and 2-4 pairs of lateral teeth, whose size decreases from the center to the edge.
Infraspecific taxa.
E. strigosa glabra Wailes, 1898
It is distinguished by the absence of spines. The size and ecology are the same as those of the type form.
E. strigosa heterospina Wailes, 1912
It differs from the typical form by the presence of spines of varying length from 6 to 20 µm. The size and ecology are the same as those of the type form.
E. strigosa muscorum Wailes, 1898
It is distinguished by a wider, pear-shaped shell. Parietal idiosomes are smaller, and the spines are shorter. The length of the shell is 45—60 µm, the width of the shell is 35—45 µm, the diameter of the aperture is 12—18 µm.
