Euglypha dickensii Ogden, 1981


Diagnosis: shell ovoid, laterally compressed and composed of about two hundred and eighty elongate body plates; aperture oval or circular, surrounded by between eleven and fifteen, evenly spaced, denticulate apertural plates. In a few specimens additional apertural plates are seen in the second circle of plates around the aperture. Each apertural plate is roughly circular, from 5.6-6.4 µm in length and 3.8-4.4 µm in width. The dentate edge has a large, thick, distinctly curved, median process with a terminal pointed tooth, this is flanked on each side by a medium outward facing tooth and one or two smaller teeth. The denticular thickening equates with the normal shell thickness at the position of the small teeth. The body plates are elongate, ranging from 5.1-6.2 µm in length and 1.6-2.5 µm in width, and are arranged in alternate longitudinal rows. Around the mid-body region there are some randomly distributed pointed body plates. These pointed plates vary from normal plates with a small shape spike, about 6.9 µm long, to tapered spines about twice the length, 9.1 µm, of a normal body plate. Although there is variation in the dimensions of these pointed body plates, their presence in a mid-body position is a reasonably stable feature.


Dimensions: see above


Ecology: Sphagnum and other mosses, also in sediments.


Remarks: The species described here is similar to three species previously reported from soil samples, namely E. capsiosa Couteaux, 1978, E. cuspidata Bonnet & Thomas, 1960 and E. simplex Decloitre, 1965. It has similar dimensions to E. simplex but differs in the shapes of the aperture plates, which in the latter species have a distinct diamond-shape. Both E. capsiosa and E. cuspidata are smaller species with fewer body and apertural plates, and again differ in the shape of the aperture plates. E. dickensii is distinct in size, dentation of the apertural plates and the presence of pointed body plates in the mid-body region.