Puytoracia bergeri
Puytoracia bergeri from Bonnet, 1970

Puytoracia bergeri  Bonnet, 1970

Diagnosis: Shell ovoid, elongated, rather close to that of Trinema enchelys. Ventral side slightly flattened, dorsal surface domed. Pseudostome of the plagiostome type, with the opening in the plane of the ventral surface or in a very slightly oblique plane with respect to the latter. Pseudostome  circular or slightly elliptical. In the latter case, the pseudostome’s major axis is perpendicular to that of the test. The pseudostome is bordered by a row of about twenty sub-circular, nested scales, each bearing a strong central rectilinear denticulation bordered by two denticles which are at the limit of visibility under a light microscope. The typical thorny chitinoid necklace of the genus Trinema seems to be lacking, but only an examination under the electron microscope will shed light on this point.
Shell consisting of siliceous, endogenous, hyaline, elliptic scales, 7 X 4 μm on average, separated, very rarely joined (and then without appreciable superposition). Free space occupied by a second series of much smaller scales and also elliptic. There may be a very slight overlap between small and large scales, but in general, the contact seems to be punctual. Colorless hyaline cement

Dimensions: Length of the test (long axis): 48 to 50 μm; width: 26 to 27 μm. Pseudostomal diameter: 8 to 9 μm; when the pseudostome is elliptical, it measures about 8 X 10 μm.

Ecology: Soil, acid forests. Quebec, Canada

Remarks: According to Bonnet (1970) this genus is easily distinguished from the genus Corythion by the presence of two classes of scales on the body. The elliptical shape of the scales and their arrangement, which does not approach any of the processes described in the Trinema allow to avoid any confusion with the latter kind.

References: Bonnet, L., 1970. Nouveaux Thécamoebiens du Sol, Bull. Soc. Hist. Nat. Toul.,106:3-4

Ferry Siemensma, created March 3, 2019; last modified October 16, 2024
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