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Diatoms of the United States is now known as Diatoms of North America.
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An internal, silica ledge that projects into the cell interior from the collum. The ringleiste is found only in the genus Aulacoseira and is variously developed in different species of the genus.

Alternative Term


The term sulcus is sometimes used, particularly with *A. ambigua*. The hollow ringliste may be called a 'U-shaped sulcus'.


Barber, H.G. and Haworth, E.Y. (1981). Guide to the Morphology of the Diatom Frustule. Freshwater Biological Association, 112 pp.