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Genus Porosia

Shell is pyriform, with rounded posterior end, laterally compressed. In front view two distinct lateral depressions with two large invaginated pores are situated on each side, which are connected by internal tubes as in genus Certesella. In profile, small lateral pores can be observed, just anterior to the large pores. The lateral keel can (or cannot) be present surrounding 1/3 of posterior lateral margin (keel is important distinctive character between Porosia species: Porosia bigibbosa – lacking of lateral keel, Porosia paracarinata – presence of lateral keel). Shell is composed of euglyphid shell plates embedded in unstructured cement. Aperture is curved, surrounded with organic lip. Habitat: Sphagnum mosses, litter, soil, rare genus. This genus is closely related to Certesella but lacks the punctuated neck. Type species: Porosia bigibbosa Jung, 1942