phyllopoda

from The Century Dictionary.

• noun An order of entomostracous crustaceans, the leaf-footed crustaceans, sometimes forming (with Ostracopoda and Cladocera) a suborder of Branchiopoda.
• noun In conchology, in J. E. Gray's classification (1821), one of several orders of Conchophora, containing dimyarian bivalve mollusks having the foot lamellar or elongate.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) An order of Entomostraca including a large number of species, most of which live in fresh water. They have flattened or leaflike legs, often very numerous, which they use in swimming. Called also Branchiopoda.