Schwabia stoutii
Schwabia stoutii, from Lueftenegger and Foissner, 1991

 

 

Schwabia stoutii (Ogden, 1983)

 

Diagnosis: The shell is ovoid or ovoid elongate, composed of mainly small, flattish particles of siliceous material, including quartz, diatom frustules and shell plates from smaller testate amoebae. It is extremely fragile, several specimens having collapsed in preparation, and hence the apparent lateral flattening of the specimen shown in Fig. 38c. Organic cement is seen only as small threads due to the regular overlapping of the shell components (Fig. 38e). The aperture is roughly circular, small and appears to be recessed, but this latter feature may be due to structural fragility.

 

Dimensions: Length 47-59 µm, breadth 33-36 µm, diameter of aperture 9-12 µm (n=4).

 

Ecology: Sphagnum moss, Wales and Austria.

 

Remarks: S. stoutii was described by Ogden (1983) as a Difflugia species, but nor he nor Lueftenegger and Foissner (1991) have seen any living specimens. They describe a fragile, elongate ovoid shell covered with flattish particles and with a small aperture. This description closely resembles Schwabia species, which I've observed several times: elongate ovoid shells with a thin smooth wall, a small aperture and filose pseudopodia. Therefore I'm pretty convinced that Difflugia stoutii represents a Schwabia species and therefore I transfer Difflugia stoutii to genus Schwabia.