Caenomorpha sapropelica is very common in most of my sampling localities. Especially in the Purren pond Caenomorpha sapropelica can be found reliably. The anterior part of the body, with apical dome and the circumferential adoral zone occupies about 2/3 of the body length, while the caudal spine occupies about 1/3 of the body length. Caenomorpha sapropelica is a fast swimmer, rotating around its longitudinal axis. The very long cilia, which originate dorsally on the apical dome, perform a rudder-like movement in the process. I could never observe a thigmotactic attachment of these long cilia to the subtrate. They are also not fused to form cirri as in Caenomorpha medusula, but rather soft and flexible. The mouth opening is located approximately at the level of the contractile vacuole. However, the cytopharynx is directed towards the anterior end (s. fig 5 b). The adoral zone begins dorsally, to the left of the two rows of apical rows of cilia, and completely encircles the body to the mouth opening. Here, the adoral membranelles lie in a furrow covered by the overhanging margin of the apical dome (s. fig. 5b). The perizonal stripe runs in parallel to the adoral zone on the distal edge of the apical dome (s. fig. 4a and 5a). At the base of the terminal spine there is a tuft of cilia (s. fig. 2 b and 3 b). In the food vacuoles I could find mainly colorless bacteria and yellowish sulfur bacteria. In the apical dome there is an accumulation of highly refractive granules, but these are only visible in the squashed specimen. In the cytoplasm there are also highly refractive spheres (oil?) and numerous symbiotic bacteria (s. fig. 6).