a. Zool. [f. Gr. ἀ not + χλαμύδ-α (χλαμύς) cloak, mantle + -ATE2.] Of certain Mollusks: Having no mantle.

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1877.  Huxley, Anat. Inv. An., viii. 510. In the achlamydate forms true gills are usually absent.

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