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Diatoms of the United States is now known as Diatoms of North America.
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Psammothidium semiapertum

(Hust.) Aboal in Aboal, Alvarez-Cobelas, Cambra and Ector 2003      Category: Monoraphid
BASIONYM: Cocconeis semiaperta
SYNONYM(S): Achnanthes hintzii Lange-Bert. and Krammer 

Psammothidium scoticum


Psammothidium subatomoides

SEM scalebar = 2 ┬Ám

Site ID: ANSP NRSA0151

Site Name: Unnamed Stream, South Dakota

Latitude: 47.280013

Longitude: -101.177966

Caption: Internal view of raphe valve

Contributor: - July 2011