Definition of "mollusca" [‖Mol•lus•ca]

• One of the leading divisions of invertebrated animals; an extensive series of invertebrates whose bodies are soft, without any jointed legs, and commonly covered with a hard shell in one, two, or more pieces, and whose principal parts are neither segmented into a series of longitudinal rings, as in insects, crustaceans, and worms, nor radiately arranged, as in echinoderms; the mollusks, as the univalve or bivalve shell-fish of ordinary language. (noun)

The Century Dictionary (Public Domain)

• "In the animal kingdom, the mollusca are the rasorial type, which, however, only shews itself there in their soft and sluggish character, and their being very generally edible."
• "All kinds of shell-fish are called "mollusca," have white blood, and breathe not only in the water, but also in the air."
• "I should be throwing up or running or studying the internal lay of crayfish and mollusca."