Cryptodifflugia Penard, 1890

Shell oval, egg-shaped, pyriform with a short neck, circular or oval cross-section, with adhering foreign particles or smooth surface, colorless, yellow or brown, composed of an outer proteinaceous material usually lined, aperture terminal, circular or oval. Pseudopods are in the form of ectoplasmic anastomosing reticulolobopods.

Type species. Cryptodifflugia oviformis Penard, 1890.

Ecology. Most of the species of the genus Cryptodifflugia are freshwater and dwell in lake sediments and on a surface of submerged water vegetation. They also can be found in various terrestrial biotopes such as Sphagnum mosses in wetlands, wet green mosses on soils and rocks, forest litter, sometimes in the rhizosphere. Few species inhabit interstitial spaces in marine sands (Golemansky 1970, 1979, 1981), i.e. Cryptodifflugia brevicolla, C. lanceolata, C. paludosa, C. psammophila.

Most of the species are rarely detected in field samples. Few of them, namely C. compressa, C. crenulata, C. oviformis, C. oviformis f. fusca, C. sacculus are cosmopolitic and may form dominant set of communities.

Geographical distribution. Species of the genus Cryptodifflugia are found in Nearctic, Palaearctic, Africotropical, Indomalayan, Australian, Neotropical, Oceania Realms, and particularly in Africa, Australia, Belgium, Bulgaria, Canada, Czech Republic, England, Holland, Hungary, Germany, Finland, France, India, Ireland, Italy, Poland, Russia, Spain, Switzerland, Japan, Sumatra, USA, Vietnam.