What is (a) The back of an animal. (b) The dorsal piece of a somite of an articulate animal. (c) One of the dorsal plates of the operculum of a cirriped called?

tergum — (a) The back of an animal. (b) The dorsal piece of a somite of an articulate animal. (c) One of the dorsal plates of the operculum of a cirriped. (Webster's 1913.)

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