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Updated Description of the Genus Androsina Lévy, 1977
Androsina is a monotypic genus that encompasses only a single species, the type species Androsina lucasi (Lévy 1977). This taxon is characterized by a multi-chambered, planispirally coiled, compressed test (or shell) with a two-layered porcelaneous wall that is constructed of high-magnesium calcite. The juvenile stage of the test is involutely coiled; subsequent ontogenetic stages are evolutely coiled with a flabelliform mode of chamber addition. And, the terminal ontogenetic stage is uniserial and flaring. Sutures (contact between chambers) are curved in the coiled stage, and strongly arched in the flabelliform and uniserial stages. The chambers are of relatively constant height, greater in width than height, with a chamber surface that is slightly inflated. The surface of the chambers is covered by rounded. Each chamber possesses multiple apertures arranged in rows and situated in longitudinal furrows along the apertural face. Two rows of apertures are present in the last-formed chambers of megalospheric tests. Up to four rows of apertures are present in the last-formed chambers of microspheric tests. The apertures are oval in shaped and longitudinally elongated, and bordered by a rounded, imperforate rim. The apertural face is ornamented with haphazardly dispersed pseudopores. The internal structure of the chambers consists of narrow buttresses and a centrally located median blade.
Live individuals possess endosymbiotic chlorophyte algae that impart a characteristic blue-green coloration to their cytoplasm (Hallock and Peebles 1993, Lévy 1977, Pawlowski et al. 2001). The chlorophyte algal endosymbionts isolated from the type species, Androsina lucasi, are most closely related to Chlamydomonas hedleyi, the chlorophyte endosymbiont of Archaias angulatus (Lee et al. 1974), and other unnamed species of Chlamydomonas isolated from closely related archaiasine foraminiferans (Pawlowski et al. 2001).