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Keywords from Image Description:
Diatomaceae of Philadelphia Plate . follows PLATE Fig Gyrosigma strigilis Wm Sm Cl Gyrosigma balticum Ehr Cl Gyrosigma hippocampus Ehr Gyrosigma simile Grun Gyrosigma acuminatum Kuetz Cl Gyrosigma scalproides Rab Cl Gyrosigma parkeri var stauroneioides Grun Gyrosigma spencerii var nodifera Grun Gyrosigma fasciola Ehr