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Genus Pontigulasia

Shell is pyriform, circular or slightly compressed in cross-section, sometimes with a constriction between the main body and the neck. In the region of the constriction the shell is divided internally into two parts by a narrow mainly organic bridge with few attached mineral particles, which connects both broad sides. Shell is composed mainly of agglutinate mineral particles with some diatom frustules. Aperture is terminal, circular. Ecology: freshwater, mosses. Type species: Pontigulasia rhumbleri Hopkinson, 1919