Keywords: Walcott Cambrian Geology and Paleontology II plate 30.jpg Plate 30 Middle Cambrian Crustaceans Bidentia Emeraldella and Burgessia 1 Bidentia difficilis <small>Walcott</small> 2 Emeraldella brocki <small>Walcott</small> 3 Burgessia bella <small>Walcott</small> 4 Burgessia bella <small>Walcott</small> Charles D Walcott Middle Cambrian Branchiopoda Malacostraca Trilobita and Merostomata Smithsonian Miscellaneous Collections Volume 57 Number 6 Publication 2051 City of Washington Published by the Smithsonian Institution March 13 1912 1912 Creator Charles Doolittle Walcott PD-old-80 Walcott Cambrian Geology and Paleontology II plates Walcott Cambrian Geology and Paleontology II plates missing identification |