Difflugia lanceolata, with distinct organic collar – 138 µm

 

Difflugia lanceolata Penard, 1890

Diagnosis: Shell elongate and tapering at both ends, composed of siliceous angular particles arranged so that the sides appear polished and smooth; aperture circular and surrounded by an organic collar.

Dimensions: Length 116-260 µm; breadth of shell 46-72 µm. My measurements 138-200 µm.

Remarks: The shell may sometimes be more sharply pointed in the aboral region, but the clean outline of this species is the main distinguishing feature.
Probably a test of this species has been described and depicted by Ehrenberg (1832) as D. oblonga!

Difflugia lanceolata

 

Shells 145-170 µm long, all from the same sample, Den Treek, Amersfoort – Photos stacked

 

Difflugia lanceolata
 
Shells 154-174 µm long; the first two shells from Den Treek, the right one from the Laegieskamp. The second shell was photographed in DIC.
Difflugia lanceolata
Shells 200 µm – 185 µm 130 µm. All three shells were found in a sample from a location near the city of Lemmer, Friesland.
Difflugia lanceolata
Drawing: Penard, in Faune Rhizopodique du Bassin du Léman, 1902

 

Difflugia lanceolata

 

 

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