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Keywords from Image Description:
Diatomaceae of Philadelphia Plate . follows PLATE Fig Navicula elegans Wm Sm Navicula elegans var cuspidata Cl Navicula grevillei Ag Cl Navicula libellus Greg Navicula palpebralis Brb Navicula rhyncocephala Kuetz Navicula cryptocephala Kuetz Navicula longa Greg Ralfs Pinnularia brbissonii Kuetz Cl Pinnularia borealis