Keywords: Walcott Cambrian Geology and Paleontology II plate 19.jpg Plate 19 Middle Cambrian Annulata Ottoia Hyolithes and Selkirkia 1 Ottoia prolifica <small>Walcott</small> 2 Ottoia prolifica <small>Walcott</small> 3 Ottoia prolifica <small>Walcott</small> 4 Ottoia prolifica <small>Walcott</small> 5 Ottoia prolifica <small>Walcott</small> 6 Selkirkia major <small> Walcott </small> 7 Hyolithes carinatus <small>Matthew</small> 8 Selkirkia fragilis <small> Walcott </small> 9 Selkirkia gracilis <small> Walcott </small> Charles D Walcott Middle Cambrian Annelids Smithsonian Miscellaneous Collections Volume 57 Number 5 Publication 2014 City of Washington Published by the Smithsonian Institution September 4 1911 Creator Charles Doolittle Walcott 1911 PD-old-80 Walcott Cambrian Geology and Paleontology II plates Walcott Cambrian Geology and Paleontology II plates missing identification |