Keywords: Walcott Cambrian Geology and Paleontology II plate 06.jpg Plate 6 Middle Cambrian Trilobita and Merostomata Neolenus and Sidneyia 1 Neolenus serratus <small> Rominger </small> 2 Neolenus serratus <small> Rominger </small> 3 Sidneyia inexpectans <small> Walcott </small> Charles D Walcott Middle Cambrian Merostomata Smithsonian Miscellaneous Collections Volume 57 Number 2 Publication 2009 City of Washington Published by the Smithsonian Institution April 8 1911 Creator Charles Doolittle Walcott J M Jessup 1911 PD-old-80 Walcott Cambrian Geology and Paleontology II plates Walcott Cambrian Geology and Paleontology II plates missing identification |