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Keywords from Image Description:
Walcott Cambrian Geology and Paleontology II plate . Plate Middle Cambrian Medusa and Holothurian Peytoia and Eldonia Peytoia nathorsti WalcottWalcottWalcott Charles Walcott Middle Cambrian Holothurians and Medusae Smithsonian Miscellaneous Collections Volume Number Publication City of Washington Published by the Smithsonian