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FMIB Calveria fenestrata Wyville Thomson One of the fourvalved pedicellariae.jpeg Calveria fenestrata Wyville Thomson One of the fourvalved pedicellariae Subject Sea urchins Calveria Tag Invertebrates Cite book Depths of the Sea an account of the General Results of the Dredging Cruises of SS 'Porcupine' and 'Lightning' During the