What is pl. (Zoöl.) A genus of simple ascidians, which formerly included most of the known species. It is sometimes used as a name for the Ascidioidea, or for all the Tunicata called?

ascidium — pl. (Zoöl.) A genus of simple ascidians, which formerly included most of the known species. It is sometimes used as a name for the Ascidioidea, or for all the Tunicata. (Webster's 1913.)

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