The genus Androsina was first described by Lévy (1977: 418). The original diagnosis is as follows: “Test comprimé, lisse, planispiralé, flabelliforme puis sub-annulaire au stade adulte. Structure interne très particulière, caractérisée par une cloison équatoriale ajourée et par des plissotements sous-épidermiques. Ouvertures disposées en lignes sur la face orale.”
The English translation of the original diagnosis as follows: Test compressed, smooth, planispiral, flabelliform, then sub-annular in the adult stage. The internal structure is very distinct, characterized by a perforated equatorial partition and by subepidermal folds. The apertures are arranged in rows on the apertural face.
The genotype (type species) of Androsina Lévy is Androsina lucasi Lévy, 1977, by original designation (Lévy 1977: p. 418). The original publication states that the holotype is deposited in the Laboratoire de Paléontologie, Muséum national d’Histoire naturelle in Paris (Specimen number: F.G. 545). The paratypes are deposited in the Historical Geology laboratory of the University of Paris VI (Université Marie-et-Pierre-Curie).
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).
