P. hemisphaerica – after Penard, 1902 (He notices that the aperture of the two left shells is drawn too small!)
Phryganella hemisphaerica Penard, 1890
Diagnosis: Shell hemispherical, yellow to brownish, rather transparent, embedded with very variable xenosomes of quartz and diatoms and sometimes completely covered with diatom frustules. Pseudostome not invaginated. Aperture large, up to half the diameter of the shell. Nucleus spherical with a large granular nucleolus.
Dimensions: Penard (1902): shell diameter 41-55 µm, also 25-40 µm at other locations.
Habitat: Freshwater.