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Eumetazoa (metazoans)
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Bilateria (bilaterally symmetrical animals)
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Protostomia (protostomes)
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Mollusca (clams, snails, squids, and relatives)
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Class Gastropoda
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Order Cephalaspidea
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Family Retusidae
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Genus Coleophysis
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Genus Cylichnina
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Genus Pyrunculus
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Genus Relichna
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Genus Retusa
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Genus Volvulella
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