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''Cassidulina'' is a foraminiferal genus described in the Treatise Part C. (Loeblich & Tappan, 1964), as having a free, lenticular test, with central boss of clear calcite on either side. Chambers are biserially arranged, enrolled planispirally with a subangular to keeled periphery. The wall is calcareous, hyaline (glassy), optically granular, perforate. The surface is smooth with a polished appearance. Sutures are radial to oblique, straight or curved. The aperture is a narrow arched slip at the base of the apertural face, partly closed by an apertural place. (Loeblich and Tappan 1988) The taxonomy of ''Cassidulina'' is rather stable, and is included in the Cassidulinidae at least as far back as Cushman, 1950. Related genera include ''Cassidulinella'', ''Favocassidulina'', ''Globocassidulina'', and ''Buriela''. ''Cassidulina'', itself, is cosmopolitan, with a stratigraphic range extending from the Upper Eocene to recent. ==References== *Joseph A. Cushman, 1950. Foraminifera, their classification and economic use. Harvard University Press, Cambridge, Massachusetts. 4th edition, 1950 * Alfred R. Loeblich, Jr. and Helen Tappan, 1964. Sarcodina, chiefy "Thecamoebians" and Foraminiferida. Treatise on Invertebrate Paleontology, Part C, Protista 2. Geological Society of America and University of Kansas Press, 1964. *Alfred R. Loeblich, Jr. and Helen Tappan, 1988. Forminiferal Genera and their classification. Geological Survey of Iran, (e-book) 2005. () 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cassidulina」の詳細全文を読む スポンサード リンク
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