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Diatoms of the United States is now known as Diatoms of North America.
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Perforation, or pore, in the diatom valve. Usually many are grouped to form a stria. The plural form is areolae.

The shape of the areola can be important in diatom taxonomy, and may be lineolate, punctate, loculate, or in the shape of a letter C.

Alternative Term


Singular of puncta. A general term for a round or oval perforation in the silica wall of a diatom.


Round, F.E., Crawford, R.M. and Mann, D.G. (1990). The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp.